Nuova ricerca

Nora Maria ANDREOLA

Personale tecnico amministrativo presso: Dipartimento di Ingegneria "Enzo Ferrari"


Home | Curriculum(pdf) |


Pubblicazioni

2018 - GASIFICATION OF BIOMASS FROM RIVER MAINTENANCE AND CHAR APPLICATION IN BUILDING MATERIALS PRODUCTION [Articolo su rivista]
Vezzali, Vittorio; Andreola, Nora Maria; Barbieri, Luisa; Lancellotti, Isabella; Pozzi, Paolo; Allesina, Giulio; Pedrazzi, Simone; Tartarini, Paolo
abstract

This paper exposes the research activities regarding REBAF (Energetic Recover of River Biomasses) project, focused on the maintenance operations self-sustainability of the Secchia river (Italy). Poplar was found as the most abundant and representative wood plant of Secchia riverbanks, with a good behavior during gasification process: from 1 hectare of maintenance every three year, it was possible to produce 23 MWh of electrical power and 31 MWh of thermal power. The biochar obtained was characterized and mixed with local red clay to create both lightweight aggregates (LWAs) for green roofs applications and bricks. Ashes coming from the gasifier cyclone were characterized and used to create bricks. The aims are the saving of raw materials and the obtaining of weight-lightened products with high porosity. Biochar and ashes were found to be suitable for this purpose given their organic carbonaceous nature, according to X-ray diffractometry, Loss on Ignition (LOI) and TG-DTA results. Application on LWAs by substituting 15%wt of the clay with biochar leads to a weight-lightening of the material. To optimize LWAs pH, spent coffee grounds (SCG) were added with proportion of 85% clay-15% biochar/SCG. A greater decrease in weight and pH values in the neutrality range were observed. Adding 20%wt biochar or ashes on bricks led to a significant reduction of materials bulk density (from 2 to 1.5 g/cm3) and the achievement of 40-45% porosity. With higher additions (until 40%wt) bulk density gets lower (1.2 g/cm3–1.3 g/cm3), but the material results weaker with a worst mechanical strength.


2018 - Investigation of the relationship between the condensed structure and the chemically bonded water content in the poly(sialate-siloxo) network [Articolo su rivista]
Melele, Sorelle J. K.; Tchakouté, Hervé K.; Banenzoué, Charles; Kamseu, Elie; Rüscher, Claus H.; Andreola, Fernanda; Leonelli, Cristina
abstract

The main objective of this work was to investigate the relationship between the condensed structure and the chemically bonded water content in the metakaolin-based geopolymer network. The kaolin used in this work as an aluminosilicate source was transformed to metakaolin by calcination at 700 °C. The powder of the waste glass and the silica fume were used as silica sources for the synthesis of the hardeners, dissolving with caustic soda solution. The obtained hardeners were characterized by infrared spectroscopy and MAS-NMR 29Si. The metakaolin and the hardeners were used for producing geopolymers cements. The synthesized products were characterized by X-ray diffractometry, infrared spectroscopy, mercury intrusion porosimetry, scanning electron microscopy, MAS-NMR 29Si and 27Al, thermal analyses (TG and DSC) and compressive strength. The results show that the compressive strength of geopolymer cements using hardener from silica fume and the one from waste glass are 61.93 and 25.51 MPa, respectively. The microstructure (SEM observations) of geopolymer cements obtained using hardener from silica fume is homogeneous, compact and dense with an average pore diameter around 13 nm. Whereas, the one obtained using hardener from waste glass are heterogeneous and contains larger pores (with average pore diameter around 168 nm). MAS-NMR 29Si and 27Al results show that the specimen obtained using hardener from the silica fume contains more aluminum in four-fold coordination in its network than the ones using hardener from waste glass. This indicates a higher degree of crosslinking of poly(sialate-siloxo) chains which could lead to a smaller pore sizes and a higher water uptake in the structure of the sample. The amount of chemically bonded water contained in the network of geopolymer cements using hardeners from waste glass and silica fume were 6.82 and 11.23%, respectively, as determined from weight loss in the range 100–300 °C. All these results indicate that the higher content of chemically bonded water in the network of geopolymer cement obtained using hardener from silica fume is related to the much smaller average pore size diameter and the hydrophilic character of aluminum, which reveals obviously better mechanical and microstructural properties of the specimen. This could indicate here a higher degree of condensation using silica fume based hardener for geopolymerization.


2018 - Rice Husk Ash (RHA) Recycling in Brick Manufacture: Effects on Physical and Microstructural Properties [Articolo su rivista]
Andreola, F.; Lancellotti, I.; Manfredini, T.; Bondioli, F.; Barbieri, L.
abstract

In this study RHA was used as silica source in the obtainment of clay bricks. Different compositions were prepared, substituting the clays with diverse percentages of RHA (0–20 wt%) and requested water contents. The pastes obtained were extruded in laboratory, dried and then fired in an industrial camera kiln. Technological tests were performed after drying (linear shrinkage and naphtha absorption) and firing [(24-h immersion) water absorption, linear shrinkage, weight loss, average flexural strength] steps. Besides, to analyze the effect on the microstructure and mineralogy, SEM/EDS and XRD analysis of the fired bricks were performed. From the tests conducted it is possible to note that RHA content contributes to reduce the linear shrinkage during drying while an opposite effect is observed for the water absorption. Regarding mechanical test, the products containing up to 5 wt% of RHA are in according to the recommended values for roof. Bricks containing higher amounts of RHA could be used in building manufacturing (light weighted faced load bearing walls) where moderate strengths and penetration protection (porosity/permeability) are required. The carbon unburned present in the RHA contributes to increase the final porosity and the weight loss of the bricks.


2018 - Role of ɣ-Al2O3 on the mechanical and microstructural properties of metakaolin-based geopolymer cements [Articolo su rivista]
Tchakouté, Hervé K.; Kamseu, Elie; Banenzoué, Charles; Rüscher, Claus H.; Andreola, Fernanda; Tchamo, Claudia C. L.; Leonelli, Cristina
abstract

The main target of this work is to investigate the influence of ɣ-Al2O3 on the properties of metakaolin-based geopolymer cements. The kaolin used as starting material for producing geopolymer cements contains approximately 28 and 64% of gibbsite and kaolinite, respectively. This kaolin was transformed to metakaolins by calcination at 500, 550, 600, 650, and 700 °C for 1 h. Gibbsite contained in kaolin was transformed to γ-Al2O3 during the calcination process. The hardener was obtained by mixing commercial sodium silicate and sodium hydroxide solution (10 M) with a mass ratio sodium silicate/sodium hydroxide equal to 1.6:1. Geopolymer cements, GMK-500, GMK-550, GMK-600, GMK-650, and GMK-700, were obtained using the prepared hardener with a mass ratio hardener/metakaolin equal to 0.87:1. It could be seen that the specific surface area of metakaolins decreases with increasing the calcination temperature of kaolin owing to the formation of the particles of γ-Al2O3. The compressive strengths 18.21/29.14/36.61/36.51 increase in the course GMK-550/GMK-600/GMK-650/GMK-700. The X-ray patterns and micrograph images of geopolymer cements, GMK-600, GMK-650, and GMK-700, indicate the presence of γ-Al2O3 in their structure. It was typically found that γ-Al2O3 remains largely unaffected during the geopolymerisation, and therefore could act as an inert filler and reinforce the structure of geopolymer cements. [Figure not available: see fulltext.].


2017 - New fired bricks based on municipal solid waste incinerator bottom ash [Articolo su rivista]
Taurino, R.; Karamanova, E.; Barbieri, L.; Atanasova-Vladimirova, S.; Andreola, F.; Karamanov, A.
abstract

The main objective of this work was to study the sintering process and technological properties of new fired bricks based on high amount of post-treated municipal solid waste incinerator bottom ash and refractory clay. In addition, the effect of the minor addition of flux (Na2CO3) or reinforce (corundum) was also highlighted. Several methods were used to study the effect of compositions variations on the sintering process, structure and the mechanical characteristics of the test briquettes. Differential thermal analysis (TG/DTA) and dilatometry techniques were applied to study the thermal behaviour while scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy and high-temperature X-ray diffraction were used to elucidate the structure and the phase composition. The mechanical characteristics were estimated by micro-indentation, strength and various physical tests (porosity, linear shrinkage and water absorption, etc). The results highlight the possibility to use very high amount of municipal solid waste incinerator bottom ashes in the production of new fired bricks with good performances at all levels. It is also shown that the addition of additives managed the final properties, affecting the crystal phase formation, porosity and greatly the strength of the samples.


2017 - Structural Characterization of natural and processed zircons with X-rays and nuclear techniques [Articolo su rivista]
Damonte, L.; Rivas, P.; Pasquevich, A.; Andreola, Nora Maria; Bondioli, F.; Ferrari, Anna Maria; Tositti, L.; Cinelli, G.
abstract

In ceramic industry, zircon sand is widely used in different applications because zirconia plays a role as common opacifying constituent. In particular, it is used as a basic component of glazes applied to ceramic tiles and sanitary ware as well as an opacifier in unglazed bulk porcelain stoneware. Natural zircon sands are the major source of zirconium minerals for industrial applications. In this paper, long, medium, and short range studies were conducted on zirconium minerals originated from Australia, South Africa, and United States of America using conventional and less conventional techniques (i.e., X-Ray Diffraction (XRD), Positron Annihilation Lifetime Spectroscopy (PALS), and Perturbed Angular Correlations (PAC)) in order to reveal the type and the extension of the regions that constitute the metamict state of zircon sands and the modifications therein produced as a consequence of the industrial milling process and the thermal treatment in the production line. Additionally, HPGe gamma-ray spectroscopy confirms the occurrence of significant levels of natural radioactivity responsible for metamictization in the investigated zircon samples. Results from XRD, PALS, and PAC analysis confirm that the metamict state of zircon is a dispersion of submicron disordered domains in a crystalline matrix of zircon.


2017 - Valorization of agro-industrial wastes in lightweight aggregates for agronomic use: Preliminary study [Articolo su rivista]
Farias, Romina D.; García, Carmen Martínez; Palomino, Teresa Cotes; Andreola, Fernanda; Lancellotti, Isabella; Barbieri, Luisa
abstract

This research was focused on the valorization of agro industrial waste/by products available in the local industry with the kilometer zero (km 0) concept, as a replacement of virgin raw materials (clay) to elaborate lightweight aggregates (LWAS). The alternative raw materials were employed as pore forming agent, in order to reduce sintering temperature and energy consumption of the furnace. The three technical nutrients studied were provided for local food industries: sludge from wastewater treatment plant from brewery industry (SB), meat-bone meal (MBM) and corn cob (CC). These materials were characterized in terms of chemical (XRF and elemental analysis - CHNS) and mineralogical (XRD) composition, as well as their thermal behavior (TGA/DTA/DSC) and LOI. For the production of LWAS different percentage of waste/by product (0, 5, 10 and 15%) were mixed with three types of clays (white, black and red) in two different clay-based mixtures. With the addition of water were produced approximately spherical pellets and thermal treated at two different temperatures (900 and 1000°C) for 1 hour. Technological parameters such as bulk and absolute density, total porosity, water absorption capacity, pH, electrical conductivity and organic matter content were measured, to determine their potential use in agriculture. XRD and scanning electron microscope (SEM) were performed for the characterization of different samples. The results indicate the potential for manufacturing high quality lightweight aggregates for agronomic purposes, using relatively simple processing and low sintering temperature that contribute to the reduction of greenhouse gases to the atmosphere.


2016 - Recycling of industrial wastes in ceramic manufacturing: State of art and glass case studies [Articolo su rivista]
Andreola, Nora Maria; Barbieri, Luisa; Lancellotti, Isabella; Leonelli, Cristina; Manfredini, Tiziano
abstract

Nowadays, ceramic tile are manufactured at zero emissions permitting to recycle all by-products and part of residues derived from depuration treatments (exhausted lime, glazing sludge and polishing sludge). In addition to this environmentally friendly tendency, in the last years an increasing number of scientific studies demonstrated the feasibility to use alternative raw materials in substitution of different component of the ternary clay-feldspar-quartz system. In the first part of the paper is reported the state of the art of industrial waste recycling in the ceramic sector, with the focus on review studies related to both ceramic tiles and bricks..In the second part of the work are reported two case studies conducted by the authors with the aim to formulate ceramic bodies using alternative raw materials. New tailored compositions were obtained replacing clays, flux and/or inert compounds (higher than 60. wt%) by scraps from packaging waste glass in tiles, and cathode ray tube glasses and packaging waste glass up to 20. wt% in the brick compositions.


2016 - Thermal approach to evaluate the sintering-crystallization ability in a nepheline-forsterite-based glass-ceramics [Articolo su rivista]
Andreola, Nora Maria; Barbieri, Luisa; Lancellotti, Isabella; Martín, M. I.; Rincòn, J. M. a.; Romero, M.
abstract

A glass in the SiO2–Al2O3–MgO–Na2O system was formulated using a non-conventional silica source and other pure raw materials. The thermal stability and crystallization mechanism have been studied by means of differential scanning calorimetry (DSC). Besides, the glass ability to sintering–crystallization has been examined by optical dilatometry, a non-contact technique allowing the acquisition of dilatometric data in the viscoelastic temperature region. The experimental data were confirmed with theoretical equations. X-ray diffraction and field emission scanning electron microscopy were used to verify the crystallization study and electron scanning microscopy to examine the fired sample microstructures. The prevalent crystallization mechanism has been evaluated from different parameters derived from characteristic temperatures of non-isothermal DSC curves, namely the working range (DTTS), reduced glass transition temperature (Tgr), and the dissimilarity in crystallization temperature (DTp) between fine (< 63 micron) and coarse (fragment) glass samples.


2015 - Design of glass foams with low environmental impact [Articolo su rivista]
Mugoni, Consuelo; Montorsi, Monia; Siligardi, Cristina; Andreola, Fernanda; Lancellotti, Isabella; Bernardo, Enrico; Barbieri, Luisa
abstract

Raw materials and their granulometry play a fundamental role in ceramic tile production especially as concern the mechanical properties of the final body. Aim of the present work is to accurately investigate the role of the raw materials granulometry on the mechanical properties of a green porcelanized stoneware body. Correlations existing between the particle size distribution and flexural strength and Young's modulus of a standard gres mixture were investigated by using the Design of Experiments method. In particular, a starting mixture of clay, which composition was kept constant, feldspar and quartz, considered in two different granulometry, was used to define a statistical combination of components-mixture. After statistical analysis of the experimental data, regression models were calculated, relating the mechanical properties of the green ceramic body to the starting granulometry. Results obtained from the present study were considered for further investigations in order to produce gres with specific properties.


2015 - Effect of Additives on the Dispersion and Electrophoretic Deposition of Highly Diluted Enamel Suspensions [Articolo su rivista]
Andreola, F. ; Dignatici, M. ; Chavez-Valdez, A. ; Siligardi, C. ; Boccaccini, A.R.
abstract

This work examines the rheological behaviour of aqueous highly diluted suspensions (1 mass-%) to identify additives that may improve the application of vitreous enamel coatings by electrophoretic deposition (EPD). Slurries for EPD were prepared by ball milling frit glass in water with suspending agents. The effect of different additives in the solids concentration range from 0.2 to 2.0 mass-% on the rheological properties of coating solutions was investigated using rotational rheometry and zeta potential measurements. Different sedimentation times were observed for the tested dispersant, binder and coagulator additives. Densicer, an organic-inorganic mix additive, showed the best properties in terms of suspension stability. The high zeta potential measured with this product confirms its potential suitability as a suspension additive for vitreous enamel coatings applied by EPD.


2015 - Physical-mechanical properties of new green building materials based on glass waste [Articolo su rivista]
Taurino, Rosa; Andreola, Fernanda; Leonelli, Cristina; Manfredini, Tiziano; Gastaldi, Paolo; Barbieri, Luisa
abstract

Recently several innovative suggestions on how industrial wastes can be utilised in new products have been presented in literature, e.g. as filler or additives in concrete, incorporated in ceramic materials to produce glass-ceramics and pavement construction. In this work, metallurgical materials from secondary aluminium scrap processing and glass waste derived from treatments of packaging and fluorescent lamps were considered for fabrication of new ceramic materials using powder technology and sintering process. The effect of composition and heat treatment temperature, on the sintering process and then final properties, were evaluated. The results showed that, with the proper firing temperature, lightweight ceramic materials containing high amount of glass waste and an innovative product resulting from the processing of secondary aluminum (ArgAlum) can be produced. The low water absorption (< 1%), low density (< 2 g/cm3) and the good flexural strength (16-20 MPa) associated to relatively low sintering temperatures obtained with the addition of ArgAlum can be considered as promising initial results to obtain new green building materials.


2015 - Transformation of the geopolymer gels to crystalline bonds in cold-setting refractory concretes: Pore evolution, mechanical strength and microstructure [Articolo su rivista]
Kamseu, Elie; Djangang, Chantale; Veronesi, Paolo; Fernanda, Andreola; Melo, Uphie Chinje; Sglavo, Vincenzo Mario; Leonelli, Cristina
abstract

Two K2O-MgO-Al2O3-SiO2 based geopolymer gels with bulk chemical composition corresponding to cordierite (Co) and 1:1 mullite-cordierite (MuCo) were successfully transformed to crystalline bonds in high temperature service of cold-setting made refractory concretes. Kyanite aggregates changed the flexural strength of the gels from11 to 28 MPa due to the development of good adhesive bonds. Under thermal cycles, up to 1250 °C, the cumulative pore volume remained at 0.09 mL/g, as fromthe absence of important densification/shrinkage. However, the behavior of the cumulative pore volume curves changed from that of a matrix with a wide range of distribution of pore sizes to that, of matrix, consisting of relatively coarse grains. The latter exhibits a rise at 10 μm as void spaces created around the contact points among the coarse kyanite grains and that at 0.054 μm as poreswithin the crystalline phases (cordierite, kalsilite, leucite,mullite, enstatite) formed. Themicrostructural observations confirmed the transformation of gel pores (size around 0.01 μm) to interparticle and intergranular pores due to the crystallization. The flexural strength of refractory concretes increased from28MPa to 40MPa in agreement with the increase in the elastic modulus from 9 to 30 GPa. The crystallization was enhanced by the MgO content (being important in Co compared to MuCo) and the kyanite concentration as particles of kyanite effectively acted as phase separation and nucleation sites


2015 - Valorization of inorganic waste, end of waste and by-product for ceramics [Capitolo/Saggio]
Barbieri, L.; Andreola, F.; Taurino, R.; Lancellotti, I.; Leonelli, C.
abstract

Recycling and re-use of waste are economically attractive options for public and private actors due to widespread separate collection and the development of functional markets for secondary raw materials. The ceramic sector is particularly sensitive to this setting through re-entry into the production cycle of all by-products and partially amounts of residues derived from depuration treatment process. Besides, thanks to academic and industrial research results, there is the tendency to see different inorganic wastes, “end of wastes” and by-products as new good candidates. In the present work, two case studies, one describing ceramics with high amount of glass waste and one ceramics with different kind of wastes, end-of-wastes and by-products, are reported with a commented list of technological and environmental benefits.


2014 - Environmental friendly management of CRT glass by foaming with waste egg shells, calcite or dolomite [Articolo su rivista]
Fernandes, H. R.; Ferreira, D. D.; Andreola, Nora Maria; Lancellotti, Isabella; Barbieri, Luisa; Ferreira, J. M. F.
abstract

Panel (P) and funnel (F) glasses from Cathode Ray Tube (CRT) have been used to obtain glass foams by a simple and economic processing route, consisting of direct heating the glass powders at relatively low temperatures (650-750 °C) using different foaming agents (FA) such as egg shells, calcite, dolomite. Mixtures in different proportions of P and F glass powders were tested and the effects of composition and heat treatment temperature on the foaming behaviour were evaluated. Glass foams featuring apparent density and compressive strength values of 0.29 g/cm3 and 2.34 MPa, respectively, could be produced from a P/F ratio=1 with added 3 wt% of egg shells upon heat treating at 700 °C for 15 min. The P/F ratio was found to strongly influence the foaming behaviour and, consequently, the physical properties of the final foam glass. The relative performance of other foaming agents under a given set of experimental conditions revealed to be dependent on the type of glass (composition and thermal properties).


2014 - Preliminary studies on the valorization of animal flour ash for the obtainment of active glasses [Articolo su rivista]
Barbieri, Luisa; Andreola, Nora Maria; Bellucci, Devis; Cannillo, Valeria; Lancellotti, Isabella; A., Lugari; Rincon, J. M. a.; M., Romero; Sola, Antonella
abstract

Animal flour ash, rich in phosphorous, calcium and alkaline oxides, has been used to formulate (i) controlled-release fertilizers, since they manage to release the nutrient elements (P, K) at a low rate, and (ii) bioactive glasses. (i) Four formulations were tailored using different amounts of animal flour ash (35–48 wt%), potassium carbonate (10–25 wt%) and a fixed amount of glassy sand (40wt%) in order to get glasses and glass-ceramics. The materials were characterised from a chemical (XRF), crystallographic (XRD) and microstructural (SEM/EDS) point of view. Moreover, in order to check the ability to release the macro-and micro-nutrients, tests were conducted to determine the kinetics of glass dissolution in different media (2% citric acid solution, 1% hydrochloric acid solution and ammonium citrate solution). The results obtained allowed to confirm all samples show a very low solubility in water (less than 1%) and high values (>40%) of P, Ca, K and Na in the other media. (ii) The rich content of phosphorous and calcium oxides makes the animal waste-derived ash a potential low-cost raw material to produce bioactive glasses. The analysis was focused on a bioactive glass, named BG_Ca, whose composition comes from the standard Bioglass® 45S5, got by increasing as much as possible the CaO content to combine a controlled behaviour during processing and a good apatite-forming ability in a simulated body fluid (SBF). This preliminary investigation shows that animal flour ash is a versatile material,which may be successfully used for several applications as various as the production of fertilisers and the preparation of bioactive glasses.


2014 - Sinter-crystallization in air and inert atmospheres of a glass from pre-treated municipal solid waste bottom ashes [Articolo su rivista]
A. Karamanov; L. Maccarini Schabbach; E. Karamanova; F. Andreola; L. Barbieri ; B. Ranguelov; G. Avdeev; I. Lancellotti
abstract

Glass powders, obtained after vitrification and milling of iron-rich Municipal Solid Waste Bottom Ashes (MSWA), were studied towards manufacture of sintered glass-ceramic material. The crystallization kinetics was investigated both in air and argon atmospheres by non-isothermal Differential Thermal Analysis (DTA). The densification behaviors at different temperatures were studied with optical dilatometry. The formed crystal phases were evaluated with X-ray diffraction (XRD) and the microstructure of samples were observed by scanning electron microscopy (SEM). The investigated composition is characterized with a high crystallization trend and formation of pyroxene solid solutions and melilite solid solutions. Due to additional nucleation process and lower viscosity (because of the lack of Fe2+ oxidation) the phase formation in inert atmosphere is accelerated and is carried out at lower temperature. In the interval 800–900 °C the densification in both atmospheres is inhibited by the intensive phase formation. However, after increasing the sintering temperature up to 1120–1130 °C secondary densification is carried out, resulting in material with zero water absorption, low closed porosity and high crystallinity. Some decreasing of sintering temperature and finer crystal structure are predicted at densification in inert atmosphere.


2013 - CRYSTALLISATION AND MICROSTRUCTURE OF NEPHELINE FORSTERITE GLASS-CERAMICS [Articolo su rivista]
M.I. Martín; F. Andreola; L. Barbieri; F. Bondioli; I. Lancellotti; J.Ma. Rincón and M. Romero
abstract

This work presents the results of a study focused on the development of forsterite-nepheline glass-ceramic with the use of rice husk ash (RHA) as a silica source. The glass-ceramics were produced by a sintering process of a glassy frit formulated in the MgO-Al2O3-SiO2 base system with the addition of B2O3 and Na2O to facilitate the melting and pouring processes. The crystallisation study was carried out by depicting the TTT curve (Time-Temperature-Transformation). The mineralogical characterisation of the glass-ceramic materials was carried out using X-ray diffraction (XRD). The crystallisation activation energies were calculated by the Kissinger method. The results obtained show that nepheline (Na2O•Al2O3•SiO2) is the major crystalline phase in the temperature interval 700-950ºC and forsterite (2MgO•SiO2) predominates at temperatures above 950ºC. A study of the microstructure by scanning electron microscopy (SEM) allowed to establish the morphological evolution in both shape and spatial arrangement of the nepheline and forsterite crystals on heating.


2013 - Management of agricultural biomass wastes:Preliminary study on characterization and valorisation in clay matrix bricks [Articolo su rivista]
Luisa Barbieri; Fernanda Andreola; Isabella Lancellotti; Rosa Taurino
abstract

In this work the feasibility of using woody agricultural biomass wastes as grapes and cherrie sseeds,saw- dust,as pore forming agent,and sugar cane ash,as silica precursor,in bricks,were reported. Sawdust and grapes and cherries seeds,thanks to their organic substances content,during their com- bustion,bring an energetic support in the bricks firingphase and act as pore formi ng agent.Usually the addition of this kind of waste is limited to 10 wt.%in order to reach an equilibrium between positive (weightand shrinkage decrease and porosity increase)and negative (increase of water absorption and mechanical resistance decrease)effects.The results show that grapes and cherries seeds,added in aper- centage of 5wt.%to abrick formulation,have better influencewith respect to the sawdust,maintaining the mechanical properties of the firedbrick (950C),showing modulu sof rupture around 21–23MPa with aweight reduction of 3–10%(respectto the standard one).Regarding the sugar cane ash,the addi- tion of 5wt.%improves the mechanical properties (modulusof rupture around 27 MPa)and no weight decrease is observed.These results confirmedthe role played by this kind of agricultural waste,which thanks to its high silica content (61wt.%)is capable to demonstrate afillerand plasticity reducing effect on the brick bodies.Tests carried out highlighted that the addition of these by-products (5wt.%)do not change negatively the main technological properties measured (waterabsorption,linear shrinkage,flex-ural resistance,etc.)and permit to hypothesize their use to obtain bricks with both insulating and higher mechanical properties using apore agent forming or silica carrier alternative raw materials,respectively.


2013 - TECHNICAL SOLUTIONS TO IMPROVE RECOVERY OF SCRAPS DERIVED FROM TREATING GLASS PACKAGING WASTE [Articolo su rivista]
Fernanda Andreola; Luisa Barbieri; Davide Giuranna; Isabella Lancellotti; Rosa Taurino
abstract

Nowadays, the Italian industry is constantly oriented on innovation of products and processes in order to achieve a high level of economic and environmental sustainability. In this context, the waste management of Emilia Romagna region is very active on the Italian territory, thanks to over 2 thousand green companies engaged in such activities. This philosophy must be understood as a strategy to address current and future challenges and to strengthen our production system thanks to the support and commitment of citizens, consumers and entrepreneurs. In 2010, in Italy about 32 million of municipal waste was produced, with a rate of separate collection of 35.3%. The waste glass collected in 2012 in Italy by separate collection of packaging waste amounted to approximately 1.6 million of tons of which 71% is sent to recovery (98% intended to glassworks, 2% to alternative recovery in ceramic or building industry (Co.Re.Ve, 2012). In Italy, the glass cullet is managed by Co.Re.Ve., the Italian Consortium for the recovery of packaging glass, since 1997. The cycle of collection and recovery of this glass can be implemented in 5 phases: collection of glass packaging in the container for recycling, withdrawal and transfer of glass cullet to the treatment plant, particle size selection and subdivision of cullet glass, obtainment of scrap suitable for the glassworks (maximum 0.068% of impurities (Co.Re.Ve., 2012), implementation of new packaging containing up to 90-95% of recycled glass. Specific treatments are performed on the glass cullet to obtain very low impurities values, such as manual sorting of pollutants, screening, separation of magnetic materials, suction of lightweight bodies and separation of non - magnetic bodies and opaque bodies are applied. Despite sophisticated equipment selection, total selection of "impure glass" is not guaranteed. In accordance with the Waste Framework Directive 98/2008/EC (landfill as a last form of disposal), the glass waste not sent to glassworks requires an alternative and innovative form of disposal. Nowadays, in Italy, this fraction (contaminated by ceramic granules and high degree of organic pollutants and coarse scraps) is collected and, in particularly in the North of Italy, treated by technological plant in order to obtain secondary raw materials for both glassworks and ceramics. However, these treatments are very expansive and the materials obtained (in particular glass or ceramic sand) have high economic value sometimes not economically sustainable.


2013 - Technological properties of glass-ceramic tiles obtained using rice husk ash as silica precursor [Articolo su rivista]
Andreola, Nora Maria; M. I., Martín; Ferrari, Anna Maria; Lancellotti, Isabella; F., Bondioli; Rincón, J. M. a.; M., Romero; Barbieri, Luisa
abstract

This paper reports the results of a study focused on the obtainment of glass-ceramic by using rice husk ash (RHA) as silica precursor. RHA is a by-product generated in biomass plants using rice husk as fuel for kilns or in the rice mills to generate steam for the parboiling process. Worldwide, it is annually produced about 132 Mt of rice husk, which gives rise to a production of 33 Mt/year of RHA. Glassceramic tiles were produced by a sinter-crystallization process using a glassy frit formulated in the MgO–Al2O3-SiO2 composition system. The realized glass-ceramics were studied according to ISO rules for sintering and technological properties (water absorption, apparent density, bending strength, Young’s modulus, deep abrasion, Mohs hardness). To complete the investigation crystalline phase formation and microstructural characterization of the glass-ceramic materials was carried out using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Finally, chemical durability tests on parent glass and derived glass-ceramics were performed. The results obtained showed that it is possible to use RHA to produce glass-ceramic tiles by a sinter-crystallization process, obtaining nepheline (Na2O*Al2O3*SiO2) as main crystalline phase and forsterite (2MgO*SiO2) at 900 1C. Regarding technological features, the sintered materials showed bending strength values and Mohs hardness higher with respect to commercial glass-ceramics like NeopariesR. Other properties as water absorption (0.5%) allowed to classify these materials into the Group BIa characteristic of high sintered ceramic tiles according to European Standard rule.


2013 - The use of egg shells to produce Cathode Ray Tube (CRT) glass foams [Articolo su rivista]
Hugo R. Fernandes; Fernanda Andreola; Luisa Barbieri; Isabella Lancellotti; Maria J. Pascual; José M.F. Ferreira
abstract

Cleaned Cathode Ray Tube (CRT) (panel and funnel) waste glasses produced from dismantling TV and PC colour kinescopes were used to prepare glass foams by a simple and economic processing route, consisting of a direct heating of glass powders at relatively low temperatures (600–800 1C). This study reports on the feasibility of producing glass foams using waste egg shells as an alternative calcium carbonate-based (95 wt%) foaming agent derived from food industry. The foaming process was found to depend on a combination of composition, processing temperature and mixture of raw materials (glass wastes). Hot stage microscopy (HSM), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize foams and evaluate the foaming ability and the sintering process. The experimental compositions allowed producing well sintered glass foams with suitable properties for some functional applications with environmental benefits such as: (1) reduced energy consumption because of the low heat treatment temperatures used; and (2) materials produced exclusively from residues.


2012 - Agricultural waste in the synthesis of coral ceramic pigment [Articolo su rivista]
Fernanda Andreola; Luisa Barbieri; Federica Bondioli
abstract

This work reports the results of an evaluation of the use of rice husk ash as the source of silica in thepreparation of coral ceramic pigments. ZrSiO4eFe2O3 inclusion pigments have been synthesized by solidstate reactions evaluating the effect of the mineralizer and both silica and iron oxide precursors on thereactivity of the system. The colour developed in the derived ceramic glazes has been compared with thecolour developed in comparative pigments prepared from pure SiO2.


2012 - Post-treated incinerator bottom ash as alternative raw material for ceramic manufacturing [Articolo su rivista]
L. M. Schabbach; F. Andreola; L. Barbieri; I. Lancellotti ; E. Karamanova; B. Ranguelov; A. Karamanov
abstract

New ceramics based on 60 wt% of alternative raw material derived from post-treated municipal solid waste incinerator bottom ashes and 40 wt%of refractory clay were studied. The chemical analysis of the compositions was evaluated by ICP. The thermal and densification behavior of theceramic batches were evaluated by DTA-TG and dilatometry techniques, respectively. After that, the degree of sintering at different temperaturesand soaking times was evaluated in detail, measuring open and closed porosities, linear shrinkage and water absorption. The crystallinity at differenttemperatures (during heating and after cooling) and microstructure of the obtained samples were evaluated by high-temperature X-ray diffraction(HTXRD) and scanning electron microscopy (SEM), respectively. For these new ceramics, the experimental results highlighted sintering rangebetween 1190–1240 ◦C. In addition, the specimens demonstrated low water absorption and high crystallinity (with anorthite as main crystallinephase), leading to mechanical characteristics comparable to those of commercial ceramic products (bending strength > 40 MPa).


2012 - Valorization of MSWI bottom ash through ceramic glazing process: a new technology [Articolo su rivista]
L. Schabbach; G. Bolelli; F. Andreola; L. Barbieri; I. Lancellotti;
abstract

-


2012 - WEEE: No waste anymore but secondary raw material [Capitolo/Saggio]
F. Andreola; L. Barbieri; M. Cannio; R. Giovanardi; I. Lancellotti; P. Pozzi; E. Soragni
abstract

The management of Waste Electrical and Electronic Equipment (WEEE) is a topic of great interest, now being an integral part of the Italian D.Lgs. 151/2005. In order to protract life cycle of this waste, composed by glass, polymers and metals, a great effort is done to develop separation, reclamation, recycling and recovery techniques. This study reports the results achieved on the characterization of different materials constituting TV sets and computers, low environmental impact techniques of extraction and recovery of precious metals from electronic circuitry and the use of glassy components as secondary raw material in the ceramic field instead of virgin compounds.


2011 - Glass-ceramic materials of system MgO-Al2O3-SiO2 from rice husk ash [Articolo su rivista]
M.I. Martìn; J.Ma. Rincòn; F. Andreola; L. Barbieri; F. Bondioli; I. Lancellotti; M. Romero
abstract

This wok shows the results of a valorisation study to use rice husk ash as raw material to develop glass-ceramic materials.An original glass has been formulated in the base system MgO-Al2O3-SiO2 with addition of B2O3 and Na2O to facilitate the melting and poring processes. Glass characterization was carried out by determining its chemical composition. Sintering behaviour has been examined by Hot Stage Microscopy (HSM). Thermal stability and crystallization mechanism have been studied by Differential Thermal Analysis (DTA). Mineralogy analyses of the glass-ceramic materials were carried out using X-ray Diffraction (XRD). Results show that it is possible to use ash rice husk to produce glass-ceramic materials by a sintercrystallizationprocess, with nepheline (Na2O·Al2O3·SiO2) as major crystalline phase in the temperature interval 700-950ºC and forsterite (2MgO·SiO2) at temperatures above 950ºC.


2011 - Integrated approach to establish the sinter-cristallization ability of glasses from secondary raw materials [Articolo su rivista]
L. M. Schabbach; F. Andreola; E. Karamanova; I. Lancellotti; A. Karamanov; L. Barbieri
abstract

-


2011 - Minimization of Pb content in a ceramic glaze by reformulation the composition with secondary raw materials [Articolo su rivista]
Schabbach, Luciana; Andreola, Nora Maria; Lancellotti, Isabella; Barbieri, Luisa
abstract

In this study a commercial ceramic glaze composed by both olivine (magnesium iron silicate, (Mg,Fe)2SiO4) and commercial frits, rich in lead (about 30 wt%), was reformulated by using secondary raw materials (CRT cone glass and municipal solid incinerator post-treatment bottom ashes before and after vitrification). The waste-based products were characterized and, compared to the standard glaze, showed better acid resistance, comparable aesthetic characteristics and slightly lower stainless resistance. Environmental benefits were obtained by saving natural raw material (olivine), by reducing lead percentage in the proposed formulations (from around 30 to 5 wt%), by energy saving (for the avoided use of commercial frits) and by reducing lead content in the new compositions.


2010 - New blended cement from polishing and glazing ceramic sludge [Articolo su rivista]
F. Andreola; L. Barbieri; I. Lancellotti; M. C. Bignozzi; F. Sandrolini
abstract

Waste generated in ceramic tiles manufacturing is not usually recycled inside the productive plant, but rather disposed to landfill. This paper deals with ceramic residues from polishing and glazing processes, as constituents for innovative blended cements. New binders made up of 75% CEM I 52.5 R and 25% residues were chemically, physically, and mechanically characterized with reference to EN 197-1 requirements and the results compared with ordinary Portland cement. Mechanicalstrength development and microstructure of the relevant mortar have been investigated up to 90 days of curing, and the behavior of polishing and glazing residues as cement constituents is reported.


2010 - New polypropylene/glass composites: effect of glass fibers from cathode ray tubes on thermal and mechanical properties [Articolo su rivista]
P. Pozzi; R. Taurino; T. Zanasi; F. Andreola; L. Barbieri; I. Lancellotti
abstract

This study investigated the feasibility of using fibers obtained by the recycling of end life cathode ray tubes glasses (EOL-CRT glass) as new filler for polypropylene material. The effects of these new fiberson the mechanical properties of plastic composites were studied. Fracture surfaces were investigatedby scanning electron microscopy. Based on the findings of this work, it appears evident that these newfibers can be used instead of commercial glass fibers providing good mechanical and thermal properties.Moreover the matrix modification in the hybrid composite led to better mechanical performances.


2010 - Recycling of screen glass into new traditional ceramics materials [Articolo su rivista]
Andreola, Nora Maria; Barbieri, Luisa; F., Bondioli; Lancellotti, Isabella; Miselli, Paola; Ferrari, Anna Maria
abstract

The Cleaned cathode ray tube (CRT) glass comes from the dismantling plant of TV and PC color kinescopes and has been used to completely replace both feldspathic and inert components of a traditional ceramic body. Panel glass has been added (up to 20 wt%) to a mixture of two commercial ball clays in order to obtain laboratory tiles sintered at 12101C. Densification has been studied according to ISO rules, while sinterability has been estimated by optical dilatometry. The samples obtained showed main properties similar to commercial ceramic floor and/or wall tiles.


2010 - The recycling of MSWI bottom ash in silicate based ceramic [Articolo su rivista]
E. Rambaldi; L. Esposito; F. Andreola; L. Barbieri; I. Lancellotti; I. Vassura
abstract

-


2010 - Use of incinerator bottom ash for frit production [Articolo su rivista]
G. Barberio; P. Buttol; P. Masoni; S. Scalbi; F. Andreola; L. Barbieri; I. Lancellotti
abstract

This article presents the results of an experimental activityaimed at investigating the technical feasibility and the environmentalperformance of using municipal solid waste incinerationbottom ash to produce glass frit for ceramic glaze (glazefrit). The process includes an industrial pretreatment of bottomash that renders the material suitable for use in glazefrit production and allows recovery of aluminum and iron.The environmental performance of this treatment option isassessed with the life cycle assessment (LCA) methodology.The goal of the LCA study is to assess and compare the environmentalimpacts of two scenarios of end of life of bottomash from municipal solid waste incineration (MSWI): landfilldisposal (conventional scenario) and bottom ash recovery forglaze frit production (innovative scenario). The main results ofthe laboratory tests, industrial simulations, and LCA study arepresented and discussed, and the environmental advantages of recycling versus landfill disposal are highlighted.


2009 - Thermal treatments for the recovery of value added materials [Capitolo/Saggio]
F. Andreola; L. Barbieri; I. Lancellotti
abstract

The techniques able to incorporate wastes can be divided between cold and hot techniques. In the first group falls stabilization/solidification by both inorganic (cement, lime, clay) and organic (thermoplastic materials, macroencapsulating compounds, asphalts, polymers) reagents. The second group comprises vitrification, devitrification, and sintering. Thermal treatments, which might speed up by the use of electromagnetic irradiation, present the advantage to fix the residue with chemical bonds, changing the microstructure or morphology from hazardous to harmless.


2009 - Valorizzazione di Scarti Agroalimentari nel Settore dei Laterizi [Articolo su rivista]
F. Bondioli; L. Barbieri; F. Andreola; N. Bagnoli
abstract

Il presente studio è incentrato sulla valorizzazione degli scarti dell’industria agroalimentare, ed in particolare della filiera cerealicola, costituiti principalmente da scarti di raffinazione, di pulitura, bucce e semi, il cui utilizzo principale attualmente è come biomasse (biopower)


2009 - WEEE Problems and Perspectives: The Case of Glass Recovery in the Ceramic Industry [Capitolo/Saggio]
Andreola F.; Barbieri L.; Lancellotti I.
abstract

-


2008 - Densification and crystallization of Ba-exchanged zeolite A powders [Articolo su rivista]
Andreola, Nora Maria; Romagnoli, Marcello; Siligardi, Cristina; Manfredini, Tiziano; Ferone, C.; Pansini, M.
abstract

The effect of thermal treatment, Na content and mineralizer ion on the sintering process of Ba-exchanged zeolite A on the zeolite ! celsianthermal transformation are investigated. The powder samples containing different amounts of Na+ and Li+ were pressed at 30 MPa and thermallytreated at temperatures from 1000 to 1400 8C for times up to 5 h and subsequently were characterized by room temperature X-ray diffraction and byscanning electron microscopy. Increasing the Na residual content in the Ba-zeolite A samples improves the sintering process, even if the highest Nacontent appears to inhibit the zeolite! celsian transformation, since a new crystalline phase appears at the highest temperature. Moreover, theporosity of all samples thermally treated is quite high. Finally the manufacture of pressed samples allowed lower temperatures and times to be usedto obtain the transformation zeolite Ba-A ! monoclinic celsian, which suggests it is a potential method to prepare celsian low temperaturerefractory materials. At last an ANOVA analysis was carried out to identify the independent parameters from a statistical point of view.


2008 - New Clay Based Ceramics Using Cathode Ray Tube (CRT) Glass as Secondary Raw Material [Relazione in Atti di Convegno]
Andreola, Nora Maria; Barbieri, Luisa; F., Bondioli; Ferrari, Anna Maria; Lancellotti, Isabella; Miselli, Paola
abstract

Cleaned panel glass was added in different percentages (5-20 wt%) to a mixture of two commercial ball clays in order to formulate new clay based ceramics replacing completely both fluxing and inert components of a traditional ceramic body. The samples obtained in laboratory were fired in industrial cycle (Tmax 1200oC for 40 min). The samples obtained were characterized from densification, microstructural, mechanical and aesthetical point of view. From the results achieved samples tiles, containing up to 15 wt% of panel glass, could be classified into BIa group (WA<0.5%) (UNI EN 14411 all.G) corresponding to impervious tiles used mainly for floor or wall covering.


2008 - Recovery of precious metals from electronic scraps [Abstract in Atti di Convegno]
F. ANDREOLA; L. BARBIERI; R. GIOVANARDI; I. LANCELLOTTI; E. SORAGNI
abstract

Recovery of precious metals (PMs) is a present topic, as they are used almost in every electronicelectric device. Gold is the second PM in order of consumption (following silver) and it is almost ubiquitary in electronics where it mainly finds application to produce bonding wires in integrated circuits and as a coating for contacts and connectors. Given this, discontinued electronic and, with a minor role, electric devices may represent a primary source of PMs as gold mines or jewelery wastes. At present the recovery of gold from such waste is generally accomplished by two strategies: by oxidative thermal treatment followed by metallurgical or chemical processes or by cyanide chemical etching; both techniques do not represent the optimum as the first one deserves a great amount of energy and non-combustible pollutant slag and fumes are produced, while the second procedure comports the use of a highly pollutant agent as cyanide. The aim of this work is the characterization of different electronics scraps to evaluate the gold concentration, and the selective recovery of this metal using enviromentally-friendly techniques. In particular, a new process was developed in order to overcome such environmental and efficiency issues. The process reaches the goal of detach the gold film from the substrate by selective leaching of the supporting metal.


2008 - Recycling of CRT panel glass as fluxing agent in the porcelain stoneware tile production [Articolo su rivista]
F. ANDREOLA; L. BARBIERI; E. KARAMANOVA; I. LANCELLOTTI; M. PELINO
abstract

In the present work, the feasibility to substitute feldspar raw material in a porcelain stoneware body with Panel Cathode Ray Tube (CRT) glasswas investigated. A standard batch and a composition, where 35 wt.% Na-feldspar was substituted by CRT glass, were sintered at differenttemperatures in the range of 1000–1250 8C. The degree of the densification was studied by evaluation of the closed and total porosity, while thesintering rate was estimated by non-isothermal dilatometric measures. The variation of the crystalline phase composition was evaluated by XRDanalysis. From the preliminary study other ceramic samples with different percentages of CRT glass (i.e. 2.5, 5 and 10 wt.%) were prepared andfired in industrial kiln. The sintering parameters, the microstructure and the mechanical properties were measured and compared with the standardcomposition.


2008 - Room-Temperature Degradation of t-Zr(Pr)O2 in an Aqueous Suspension Revealed by Perturbed Angular Correlations [Articolo su rivista]
CARACOCHE MC; MARTINEZ J.A; RIVAS P.C; ANDREOLA F; F. BONDIOLI; FERRARI AM; MANFREDINI T
abstract

This paper deals with the phase stability of an aqueous suspension of tetragonal Zr0.9Pr0.1O2 (20 wt%/vol%) at room temperature as a function of the aging time. The suspension is investigated in situ using the highly localized Perturbed Angular Correlations technique. The results indicate that an almost fully reversible degradation process toward monoclinic zirconia takes place through a first-order reaction of rate constant k = 0.7-1day. Two successive diffusion mechanisms are observed that are interpreted as OH ions’ migration in the grain surface and then, as proton defects’ diffusion into the bulk.


2008 - Synthesis of chromium containing pigments from chromium galvanic sludges [Articolo su rivista]
Andreola, Nora Maria; Barbieri, Luisa; F., Bondioli; Cannio, Maria; Ferrari, Anna Maria; Lancellotti, Isabella
abstract

In this work the screening results of the scientific activity conducted on laboratory scale to valorise chromium (III) contained in the galvanic sludge as chromium precursor for ceramic pigments are reported. The valorisation of this waste as a secondary raw material (SRM) is obtained by achievement of thermal and chemical stable crystal structures able to colour ceramic material. Two different pigments pink CaCr0.04Sn0.97SiO5 and green Ca3Cr2(SiO4)3 were synthesized by solid-state reactions using dried Cr sludge as chromium oxide precursor. The obtained pigments were characterized by X-ray diffraction and SEM analysis. Furhermore the color developed in a suitable ceramic glaze was investigated in comparison with the color developed by the pigments prepared from pure Cr2O3. The characterization carried out corroborates the thermal and chemical stability of the synthesized pigments and, especially for the Cr-Sn pink pigment, the powders develop an intense color that is very similar to the color developed by the pigments obtained starting from pure Cr2O3.


2008 - “Reuse of incinerator bottom and fly ashes to obtain glassy materials”, [Articolo su rivista]
ANDREOLA F; BARBIERI L; HREGLICH S; I. LANCELLOTTI; MORSELLI L; PASSARINI F; VASSURA I
abstract

Bottom and fly ashes coming from the urban wastes incineration represent a by-product nowadays landfilled. By mixing different amount of these residues with others inert materials, such as glass cullet and feldspar waste, two vitrifiable mixtures are tailored. Glasses, obtained by means of vitrification process, are chemically stable with low leachability of contaminants and show comparable properties to those of commercial soda lime glasses. Moreover, from the thermal and mechanical characterization the tendency of these glasses to crystallise, for their transformation into glass-ceramic materials, has been evidenced.


2007 - ANALISI LCA DEL QUARZO VENTILATO [Articolo su rivista]
Andreola, Nora Maria; Barbieri, Luisa; F., Bondioli; Ferrari, Anna Maria; Lancellotti, Isabella; P., Neri
abstract

-


2007 - CRT glass state of the art. A case study: Recycling in ceramic glazes [Articolo su rivista]
F. ANDREOLA; L. BARBIERI; A. CORRADI; I. LANCELLOTTI
abstract

The management of electrical and electronic equipment waste (WEEE) is a significant problem of industrialized countries, in the last decades it has been noticed an appreciable increase of this residue, consisting of about 80% of television sets and cornputers containing end of life (EOL) cathode ray tubes (CRT). Specific technologies permit to dismantle the kinescope, obtaining different glasses with high quality level and specific chemical compositions. The presence of dangerous elements makes critical the re-use in many fields of application. The present work proposes the feasibility of CRT glass recycling in ceramic field using it into a base glaze formulation as substitute of ceramic frits. The study was conducted in two phases, laboratory scale in order to study the suitable glaze formulation and semi-industrial scale with the technological support of an Italian ceramic glaze producer. The glazes obtained have aesthetic and mechanical properties extremely similar to the standard ones. (c) 2006 Elsevier Ltd. All rights reserved.


2007 - Effect of rice husk ash (RHA) in the synthesis of (Pr,Zr)SiO4 ceramic pigment [Articolo su rivista]
F., Bondioli; Andreola, Nora Maria; Barbieri, Luisa; Manfredini, Tiziano; Ferrari, Anna Maria
abstract

In this work the screening results of the scientific activity conducted on the possibility to use rice husk ash as silica precursor for ceramic pigments are reported. Ceramic pigments were synthesized by solid-state reactions and the color developed in a suitable ceramic glaze was investigated in comparison with the color developed by the pigments prepared from pure SiO2.


2007 - Mixture of deflocculants: A systematic approach [Articolo su rivista]
M. Romagnoli; F. Andreola
abstract

In the production of ceramic tiles, during wet grinding, chemical additives are normally used to increase the solid loading of the suspensions. Commonly, mixtures of organic and inorganic chemical additives are used to reduce viscosity and costs. In literature, only few papers consider the combined effect of two or more deflocculants and a modest knowledge has developed on possible competitive or synergic interactions among them. The most common rheological additives show different behaviour depending on the clay. With mixture design it is possible to define mathematical models by means of which it is possible to engineer the rheological behaviour of a suspension. (c) 2006 Elsevier Ltd. All rights reserved.


2007 - RELEASE OF IONS FROM KAOLINITE DISPERSED IN DEFLOCCULANT SOLUTIONS. [Articolo su rivista]
F. ANDREOLA; E. CASTELLINI; G. LUSVARDI; L. MENABUE; M. ROMAGNOLI
abstract

Chem. investigations have been performed on deflocculated suspensions of kaolinite previously treated with two widely employed dispersants: sodium hexametaphosphate (NaHMP) and sodium disilicate (NaDIS). F. Andreola et al. (2006) showed remarkable differences in the rheol. behavior between untreated and treated samples. The release of ions by kaolinite dispersed in deflocculant solns. results strongly affected by the nature of the treatment. The chem. anal. of the soln. phase sepd. from the suspensions of treated and untreated kaolinite provides relevant information about the deflocculation mechanism of HMP and DIS and gives reason of the obsd. differences in the rheol. responses.


2007 - Recycling of EOL CRT glass into ceramic glaze formulations and its environmental impact by LCA approach [Articolo su rivista]
Andreola, Nora Maria; Barbieri, Luisa; Corradi, Anna; Ferrari, Anna Maria; Lancellotti, Isabella; P., Neri
abstract

AbstractBackground, Aims and Scope The interest in recycling materials at the end of their life is growing in the industry in general. As regards the Wastes of Electrical and Electronic Equipment (WEEE), an appreciable increase of these materials has been noticed in the last decades, 117 · 103 tons of WEEE have been produced in Italy in 2002 according to Ecohitech [1] and the increase in this kind of waste is three times higher than that of the municipal waste according to the FISE ASSOAMBIENTE report [2]. Within WEEE, End-of-Life Cathode Ray Tube (EOL CRT) glass, the main part of TV sets and PC monitors, is here analysed using both a technical approach to establish a possible reuse of the glass in a open-loop recycling field (ceramic industry) and a methodology (LCA) capable of providing environmental evaluations. Methods The technological characterization was performed by chemical resistance tests (UNI EN ISO 10545-13), staining tests (UNI EN ISO 10545-14) with blue methylene and potassium permanganate (KMnO4), and surface abrasion tests (UNI EN ISO 10545-7). The LCA study was conducted using the SimaPro 5.0 software and Eco-Indicator 99 as an evaluation method. Results and Discussion The good technical results, reached by using cleaned EOL CRT panel glass inside a ceramic glaze formulation instead of a commercial frit, are supported by the environmental impact evaluation, which shows a decrease of the overall potential damage (measured in Points) of 36% and, in particular, a reduction of 53% in ‘Human health’, 31% in ‘Eco-system quality’ and 24% in ‘Resources’. Conclusions This study has demonstrated that this new, open-loop recycling strategy for the CRT glass significantly reduces the environmental impact of the ceramic glaze production process. In fact, in all damage categories examined in this study, there is a minor impact. An improvement is evident in the respiratory inorganics sub-category related to the lowering of dusts mainly and to a lesser amount with NOx and SOx in the climate change sub-category, due mainly to the reduction of CO2 emission correlated to the avoided combustion of the mixture which feeds melting furnaces in the frit production. Thus, the damage decrease in ‘Ecosystem quality’ is prevalently due to the lower NOx emissions by the kilns in the frit production that is evident in the acidification/eutrophication sub-category. Finally, the significant saving in the ‘Resource’ category is principally linked to the fossil fuels sub-category, thanks to the methane saving which stokes the melting furnaces. Perspectives Furthermore, the decrease in CO2 emission (94.4%) evident in the climate change sub-category is a very important topic because it is in line with the Kyoto protocol (1997), where significant efforts have been exerted for the reduction of the green house gases emission, notably CO2. The CO2 emission is correlated to the combustion of the mixture which feeds melting kilns in the frit production, therefore the recycling of secondary raw materials, already in a glass state, can reduce the emissions of this gas. This reduction can be termed as environmental credit and it is an example of an allocation of environmental loads in a open-loop recycling, where waste from one industrial system are used as raw materials in another product system.


2007 - Valorization of Italian clay added bentonites for porcelain stoneware bodies.Study of the rheological behaviour and mechanical properties [Relazione in Atti di Convegno]
F. Andreola; C. Siligardi; T. Manfredini; C. Carbonchi; P. Danasino
abstract

This paper present the results obtained using a clayfrom Sardinia island, Italy, added with 10 wt% ofdifferent bentonites available on Italian territory inorder to obtain a decreasing of the body costs. Twoserie of bodies was prepared a first serie substitutingcompletely Germany clay and partially Ukraine clay(5wt%), a second serie substituting completely theUkraine clay into a porcelain stoneware body.Rheological measures were carried out on thesuspensions prepared in order to verify the effect of thebentonites presence on the shear and time dependence.The fired specimens were characterized across thetechnological parameters, mechanical and aestheticalproperties and compared with a standard/industrialcomposition.


2006 - ELECTRICAL BEHAVIOUR OF MATERIALS BASED ON MONOCLINIC CELSIAN DERIVED FROM CATION-EXCHANGED COMMERCIAL ZEOLITES. [Articolo su rivista]
A., Motori; F., Patuelli; A., Saccani; Andreola, Nora Maria; F., Bondioli; Siligardi, Cristina; Ferrari, Anna Maria
abstract

Abstract Monoclinic celsian has been obtained by a non-conventional way, i.e. the thermal treatment of 4A-type commercial zeolite: a stoichiometric amount of barium ions was included in the zeolite by means of a cation-exchange treatment. A small concentration of alkali ions (either sodium or lithium) was also present in the exchanged zeolite, since previous studies had underlined the positive effect of these ions on the formation of monoclinic celsian. This particular synthesis proves to be economic, due to the low-cost precursors, the low temperatures and the short times required. However, the presence of even a small content of alkali ions and a residual amorphous phase can negatively affect the insulating properties of the material, thus hindering its use in electrical insulating systems. The results so far obtained show that the material keeps good insulating properties at low temperature, but its conductivity and dielectric losses strongly increase above 200 °C. --------------------------------------------------------------------------------


2006 - Effect of sodium hexametaphosphate and ageing on the rheological behaviour of kaolin dispersions [Articolo su rivista]
F. Andreola; E.Castellini; J.M.F. Ferreira; S. Olhero; M. Romagnoli
abstract

Concentrated dispersions (35% v, v) of ceramic grade kaolin dispersed with sodium hexametaphosphate (NaHMP) were prepared at three different experimental conditions: in distilled water at 30 and 60 degrees C, and in a 5 * 10(-3) M Ca(NO3)(2)(.)4H(2)O solution, at 30 degrees C. The dispersions were kept at constant temperatures for different ageing times (2, 4, 6, 18, 24, 48 h). After each ageing period they were submitted to rheological measurements and centrifuged to measure the concentration of HMP- ion in the supernatant solution by ICP. Measurements of the electrophoretic mobility in dispersions containing Ca(NO3)(2)(.)4H(2)O and KCl as background electrolyte were also performed both in the presence and in absence of NaHMP. The results allow a better understanding of the roles played by calcium ions and ageing of kaolin dispersions in the presence of NaHMP. They also shed light on the deflocculating mechanism of NaHMP. Correlations between theological parameters and chemical properties of the dispersions could be established.


2006 - MICROWAVE THERMAL INERTISATION OF ASBESTOS CONTAINING WASTE AND ITS RECYCLING IN TRADITIONAL CERAMICS [Articolo su rivista]
C. LEONELLI; P. VERONESI; D. N. BOCCACCINI; M. R. RIVASI; L. BARBIERI; F. ANDREOLA; I. LANCELLOTTI; D. RABITTI; G. C. PELLACANI
abstract

Asbestos was widely used as a building material prior to the 1970´s. It is well known that asbestos is a health hazard and its progressive elimination is a priority for pollution prevention. Asbestos can be transformed to non-hazardous silicate phases by microwave thermal treatment. The aim of this investigation is to describe the microwave inertization process of asbestos containing waste (ACW) and its recycling in porcelain stoneware tiles, porous single-fired wall tiles and ceramic bricks following industrial manufacture procedure. Inertised asbestos powder was added in the percentages of 1, 3, and 5 wt.% to commercially available compositions and then fired following industrial thermal cycles. Water absorption and linear shrinkage of the obtained industrial products do not present significant variations with additions up to 5 wt.% of microwave inertised ACW.


2006 - Non conventional synthesis of monoclinic celsian from Ba-exhanged zeolite A: study of the effect of residual Na and forming pressure [Capitolo/Saggio]
C. Ferone; M. Pansini; F. Andreola; L. Barbieri; C. Siligardi; T. Manfredini
abstract

Four samples of Ba-exchanged zeolite A, bearing 0.27, 0.43, 0.58 and 0.74 meq/g Na residual amounts, were thermally treated in the temperature range 200-1500 °C for times up to 28 hours. The same samples were pressed at 30 and 60 MPa to manufacture cylindrical pellets, which were thermally treated at 1300 °C for 5 hours. Thermally treated materials were characterized by room temperature XRD. The sequence of thermal transformations that Ba-exchanged zeolite A undergoes (zeolite ® amorphous phase ® hexacelsian ® monoclinic celsian) and the strong mineralizing action developed by Na are confirmed. Pressing the Ba-exchanged zeolite A powder-like samples to obtain cylindrical pellets is found to expedite the sluggish final phase transition hexacelsian ® monoclinic celsian. The optimum residual Na content of Ba-exchanged zeolite A to be transformed into monoclinic celsian is assessed to range between 0.27 and 0.43 meq/g.


2006 - RF thermal plasma treatment of waste glass and its reutilization in composite materials [Articolo su rivista]
V. Colombo; E. Ghedini; G. Masini; D. Russo; F. Andreola; L. Barbieri; D. Belviso; I. Lancellotti; P. Pozzi
abstract

Fluorescent lamps glass powders are sieved in two particle size ranges and are subjected to thermal plasma in-flight treatment by injection into the discharge of a Tekna PL-35 plasma torch and reaction chamber as part of a source operated at 3MHz with a maximum power of 25kW, with Ar as plasma and carrier gas and N2 as sheath gas. The sieved powders and the plasma treated ones have been characterized by powder XRD and particle size analysis in order to verify if the plasma treatment can induce modification in the mineralogical and physical characteristics. The spherical shape of the particles have been analyzed by scanning electron microscopy. Moreover, this technique has allowed to verify if the plasma treatment can induce modification of the (qualitative) chemical composition of the powder. Results for various operating conditions and injection probe positions are presented. The spherical powders have been then introduced in thermoplastic polymer (polypropylene) in place of glass spheres usually used, and the results are compared to each others. The samples are characterized by mechanical tests (flexural strength) and microstructural analysis (SEM) in order to verify the differences in materials properties obtainable by mean of conventional and plasma assisted processes.


2006 - Role of the surface treatment in the deflocculation of kaolinite [Articolo su rivista]
F. Andreola; M.C. Romagnoli; E. Castellini; G. Lusvardi; L. Menabue
abstract

Suspensions of untreated and properly treated Na-exchanged kaolinite have been subjected to rheological investigations using sodium hexametaphosphate (NaHMP) or sodium disilicate (DIS) as deflocculants. The treatment of the clay consisted of a 24 h contact with solutions of NaHMP or DIS and separation of the resulting solid phase. This was then used to form the suspensions subjected to the rheological measurements. The results indicate that the dispersion ability of each deflocculants is remarkably influenced by the type of treatment. In particular, with respect to the untreated kaolinite, the efficiency of DIS is dramatically increased when the clay has been previously treated with a NaHMP solution. On the other hand, a decrease in the dispersant ability of NaHMP is observed from the untreated kaolinite to the one previously treated with DIS.


2005 - Applicazioni delle argille nell'industria ceramica [Capitolo/Saggio]
Andreola, Nora Maria; Manfredini, Tiziano
abstract

I ceramici “tradizionali” sono prodotti ottenuti da materie prime largamente diffuse in natura quali argille, feldspati e sabbie quarzifere foggiati generalmente a freddo e sottoposti ad opportuni trattamenti termici in grado di innescare le trasformazioni fisiche (cambiamenti di fase, passaggio dallo stato cristallino a quello vetroso e viceversa,etc) e chimiche (reazioni di decomposizione, formazione di nuove fasi cristalline) che li rendono appropriati per il loro utilizzo (Ricciardiello& Palmonari, 1996). Vengono usualmente indicati per applicazioni in edilizia (piastrelle, laterizi e sanitari), per uso domestico (stoviglieria, porcellana) e per uso industriale (porcellane tecniche e refrattari). Nel saggio vengono descritte le composizioni degli impasti per piastrelle da pavimentazione e rivestimento che negli ultimi anni hanno subito un’evoluzione importante adattandosi fondamentalmente ai cicli di cottura rapida (inferiori a 60 min.).


2005 - Cathode ray tube glass recycling: an example of clean technology [Articolo su rivista]
F. Andreola; L. Barbieri; A. Corradi; I. Lancellotti
abstract

In this study the use of 'cleaned' end of life (EOL) cathode ray tube (CRT) glass as a raw material in ceramic glazes is described. At present, the recycling and industrial utilization of CRT, a glass material from TV and computer sets, is a subject of intense research with particular regard to the so-called open-loop recycling, namely cycles different from that of the origin. However, the use of CRT glass as a secondary raw material is strictly related to the demand of high-quality raw material. The good preliminary results reached by introducing clean TV and PC monitor panel and cone glass into ceramic glaze formulations pushed research toward the setting-up of a base glaze that is exploitable for the production of pigmented, silk-screened and flame-hardened glazes (products used industrially for coating floor tiles). The aesthetic and chemical characterization of the tiles glazed by this product showed an extremely similar behaviour to originals that did not contain CRT glass. The good technical results achieved have been supported by the life cycle assessment analysis, which has demonstrated a reduction of the environmental impact of the CRT glass-containing ceramic glaze with respect to the standard one.


2005 - Glass-ceramics obtained by the recycling of end of life cathode ray tubes glasses [Articolo su rivista]
F. ANDREOLA; L. BARBIERI; A. CORRADI; I. LANCELLOTTI; R. FALCONE; S. HREGLICH
abstract

This work is concerned with open-loop recycling of end of life Cathode Ray Tubes glass (an unsolved problem when considering that in Europe almost 90% of EOL electronic goods is disposed of in landfills), focusing on the development of glass-ceramics from panel or funnel glass with dolomite and alumina, and the evaluation of the tendency towards crystallisation with particular attention on composition and thermal treatment. Glasses were melted at a temperature of about 1500 degrees C and transformed into glass-ceramics by different thermal treatments (900 degrees C to similar to 1100 degrees C temperature range and 0.5 to similar to 8 h soaking time). By using the evaluation of thermal, mineralogical and microstructural data it has been pointed out that a good degree of crystallisation is reached at about 1000 degrees C and with a high proportion of waste glass (50-75%) if 40-45% of CaO and MgO bearer (dolomite) is introduced. In this way alkaline and alkaline-earth silicate and aluminosilicate mainly develop probably with a surface mechanism.


2005 - Influence of the pozzolanic fraction obtained from vitrified bottom-ashes from MSWI on the properties of cementitious composites [Articolo su rivista]
A. SACCANI; F. SANDROLINI; F. ANDREOLA; L. BARBIERI; A. CORRADI; I. LANCELLOTTI
abstract

Municipal Solid Waste Incineration Bottom Ashes (MSWI BA) have been submitted to a thermal treatment leading to their complete vitrification. The composition and the pozzolanic activity of the vitrified, grounded bottom ashes is evaluated, as far as the mechanical and microstructural properties of mortars containing up to 30 wt. % of this fraction (on cement weight), as a replacement of the hydraulic binder. At sufficiently long curing times, modified composites exhibit higher mechanical strengths and lower porosity than those of the unmodified ones. The same mortars show lower permeation to chlorides and sulphates and the tendency to depress the expansion generated by alkali-silica reactions (ASR). 1359-5997 &COPY; 2004 RILEM. All rights reserved.


2005 - Recycling industrial waste in brick manufacture. Part 1 [Articolo su rivista]
F. Andreola; L. Barbieri; I. Lancellotti; P. Pozzi
abstract

The ongoing accumulation of industrial waste speaks to the need to seek cost-effective disposal methods. Brick manufacture would appear to be particularly promising in this regard. The present study analyzes the possibility of recycling the sludge generated in porcelain tile polishing, as well as coal, steel and municipal incinerator ash to make a special type of facing brick whose properties readily accommodate a full analysis of all the problems deriving from the incorporation of residue in its manufacture. Physical-chemical, mechanical and structural analyses were performed on bricks made with varying percentages of the different types of waste considered. This first paper reports the results of the physical and technological characterization of the products; the second part of the research will address their chemical, mechanical and structural properties.


2005 - Reutilization of waste inert glass from the disposal of polluted dredging spoils by the obtainment of ceramic products for tiles applications [Articolo su rivista]
G. Brusatin; E. Bernardo; F. Andreola; L. Barbieri; I. Lancellotti; S. Hreglich
abstract

The vitrification treatment has been successfully exploited as a solution for the disposal of polluted dredging spoils from the industrial area close to the Venice Lagoon. The addition of 20% by wt. of glass cullet to the calcined sediments in the vitrification batch provides a suitable chemical composition for the production of an inert glass, despite the compositional variations of the sediments. The obtained waste glass, after being finely ground, has been employed (i) as a raw material for the manufacture of sintered glass-ceramics, by cold pressing and single-step sintering at about 940 degrees C, and (ii) as sintering additive (the maximum addition being 10% by wt.) for the manufacture of traditional red single firing ceramic tiles, with a maximum firing temperature of 1186 degrees C. Both applications have proved to be promising: in the first case, the sintered glass ceramic product exhibits notable mechanical properties (bending strength > 130 MPa, HV approximate to 6.5 GPa); in the second case, the addition of waste glass does not modify substantially the investigated physical and mechanical properties of the traditional product (water absorption, linear shrinkage, bending strength, planarity).


2005 - Sintered glass-ceramics and glass-ceramic matrix composites from CRT panel glass [Articolo su rivista]
E. BERNARDO; F. ANDREOLA; L. BARBIERI; I. LANCELLOTTI
abstract

Sintering with simultaneous crystallization of powdered glass represents an interesting processing route for glass-ceramics, especially originating from wastes. Highly dense glass-ceramic samples may be obtained from a simple and short treatment at a relatively low temperature. In addition, glass-ceramic matrix composites may be obtained by mixing glass with suitable reinforcements. In this work sintered nepheline glass-ceramics, based on panel glass from cathode ray tubes, are illustrated. A limited addition of Al2O3 platelets caused a significant improvement in the mechanical properties (elastic modulus, bending strength, microhardness, fracture toughness), already remarkable for the un-reinforced glass-ceramic, compared with traditional nepheline glass-ceramics.


2004 - New marketable products from inorganic residues [Articolo su rivista]
F. ANDREOLA; L. BARBIERI; A. CORRADI; I. LANCELLOTTI
abstract

Ash from the incineration of municipal solid residues and from thermal power stations appear to be easily transformed to new marketable products, including glasses, glass ceramics and ceramics. Steel fly ash however presents many diificulties for insertion as a fundamental constituent into these products.


2004 - Smalti per piastrelle dal vetro di TV e monitor [Articolo su rivista]
F. ANDREOLA; L. BARBIERI; A. CORRADI; M. GARZONI; E. GUIDETTI; I. LANCELLOTTI; A. MEDICI; D. RABITTI; A. SANSONE
abstract

-


2004 - The role of sodium hexametaphosphate in the dissolution process of kaolinite and kaolin [Articolo su rivista]
F.ANDREOLA; E.CASTELLINI; T.MANFREDINI; M. ROMAGNOLI
abstract

Suspensions of kaolinite and ceramic grade kaolin in sodium hexametaphosphate solutions at different concentrations were prepared and kept at constant temperature for 4 h: the solutions obtained after centrifugation and filtration were analysed using a ICP technique to determine the concentration of significant cations. The results allowed to stress the role of NaHMP in the dissolution process of kaolinite and ceramic grade kaolin. The role of accessory minerals in ceramic grade kaolin dissolution was discussed in the light of the obtained data.


2004 - “Polveri da trattamento fumi di industria siderurgica: esperienze di inertizzazione e di valorizzazione” [Relazione in Atti di Convegno]
F. ANDREOLA; L. BARBIERI; I. LANCELLOTTI; G. POLI;
abstract

-


2003 - Comparison of various solvent media efficiency in the grinding of a frit containing zirconium oxide [Articolo su rivista]
F. Andreola; MC D'Arrigo; C. Leonelli; C. Siligardi; GC Pellacani
abstract

In the present work thermal and chemical properties of a glass-ceramic frit containing zirconium oxide are evaluated after milling in various polar and nonpolar solvents. Particle-size distribution is one of the main variables investigated to evaluate the efficiency of several solvents. Milling in various solvents does not affect the thermal properties of the glass while the presence of polar groups in the solvent molecule increases the cation release from the glass.


2003 - Delamination of italian kaolin: effect of reaction temperature and cristallinity on the urea rate intercalation [Abstract in Atti di Convegno]
L. Garrido; F. Andreola; E. Castellini
abstract

Urea is effective in kaolin delamination and cristallinity. The role of temperature in delamination has been investigated in different conditions.


2003 - Effect of ionic strength and temperature on the interaction between kaolin suspensions and sodium hexametaphosphate [Abstract in Atti di Convegno]
F. Andreola; E. Castellini; T. Manfredini; M. Romagnoli
abstract

The effect of ionic strength on the interaction between kaolin and sodium hexametaphosphate has been investigated at different temperatures.


2003 - POSSIBILITÀ DI RICICLO DI VETRO DA CINESCOPI DISMESSI PER L’OTTENIMENTO DI VETRO-CERAMICI [Articolo su rivista]
F. ANDREOLA; L. BARBIERI; A. CORRADI; I. LANCELLOTTI; R. FALCONE; S. HREGLICH
abstract

-


2002 - Chemical additives for pressure tape casting [Articolo su rivista]
F. Andreola; E. Castellini; M. Romagnoli
abstract

Suspensions of ceramic raw material and different deflocculant polyelectrolytes were prepared with a solid content of about 78% in industrial water. The rheological behavior of these suspensions was tested by evaluation of the shear dependence in a 4-step cycle and by a modified off-on procedure that reproduced the typical times involved in tape casting. The best deflocculants were found to be Na hexametaphosphate and polyacrylate, but their capability differed a little from mixtures of hexametaphosphate and Na disilicate or from ternary mixtures. The deflocculants made the suspensions slightly dilatant, had a low viscosity and yield stress values close to zero, that permitted an easy degasification of the suspensions. The additives, alone or in mixture, had adequate characteristics for use in pressure tape casting.


2002 - Recycling of the waste waters into porcelainized stoneware ceramic tiles: effect on the rheological, thermal and aesthetical properties [Relazione in Atti di Convegno]
Andreola F.; Barbieri L.; Lancellotti I.; Manfredini T.
abstract

The importance of the porcelainized stoneware production, this product reached the 36% (218.106 m2) of the total Italian production in the last year, and the impossibility to reuse both the ceramic residues and the process waste waters with the similar practice developed previously for the other typologies have brought to find new solutions to applied at this kind of wastes. The aim of the work is to evaluate the possibility to recycle waste waters, deriving from different technological ceramic cycles, inside the porcelainized stoneware body. The use of these waters does not change the parameters of the productive cycle, obtaining a final product with the similar quality and aesthetic characteristics required from the market and avoiding a possible spilling of the waste water after purification in sewers or in superficial river courses.


2002 - Rotational Rheometry used as Laboratory Technique to Test Commercial Deflocculants [Articolo su rivista]
F. ANDREOLA ; M. ROMAGNOLI
abstract

This study considers the use of rotational rheometry as a laboratory technique to control the efficiency of different commercial deflocculants on kaolin suspensions. In particular, three commercial Penta Sodium Tripolyphosphates (STPP), which are widely used in the ceramics industry, were tested. In order to characterise the Tripolyphosphate (TPP) salts, chemical and physical analyses were carried out. The aim of this study is to highlight the ability of rheometric techniques to describe the effects of the different additives with fast and easy procedures that can be utilised on industrial or laboratory scale. The rheological measures were performed on kaolin suspensions with different amounts of TPPs salts addition. As a liquid medium, industrial water with calcium and magnesium ions was simulated.


2002 - Tape casting sotto pressione di sospensioni acquose di allumina [Relazione in Atti di Convegno]
F.ANDREOLA; T.MANFREDINI; M. ROMAGNOLI
abstract

Tape casting sotto pressione di sospensioni acquose di allumina


2002 - The influence of the Mean Free Path between Particles on the apparent Viscosity of Clay Slips [Articolo su rivista]
J.B.RODRIGUES NETO; A.P.NOVAES DE OLIVEIRA; O.E.ALARCON; P. POZZI; F.ANDREOLA
abstract

Studies of the rheological behaviour of clay suspension


2002 - Urban incinerator grate ash used as raw material to produce sintered glass-ceramics [Articolo su rivista]
L. BARBIERI; F. ANDREOLA; A. CORRADI; I. LANCELLOTTI
abstract

Sintering is shown to be a very convenient alternative way to valorise urban incinerator grate ash as raw material to produce glass-ceramics. The results reached by thermal, mineralogical, physical and microstructural analysis show that it is possible to obtain sintered finished products constituted of common silicate crystalline phases (wollastonite, diopside/augite) by heat treatments with shorter time and lower temperature with respect to the bulk devitrification.


2002 - Utilisation of municipal incinerator grate slag for manufacturing porcelainized stoneware tiles manufacturing [Articolo su rivista]
F. ANDREOLA; L. BARBIERI; A. CORRADI; I. LANCELLOTTI; T. MANFREDINI
abstract

Porcelainized stoneware tiles containing up to 20 wt.% of municipal incinerator grate slag have been fabricated by cold uniaxial pressing and conventional fast firing cycles. The sinterability of these samples was investigated from density and shrinkage measurements together with mechanical (Vickers microhardness and Young's modulus) and esthetical (spot resistance and colour parameters analysis) properties. The comparison with the porcelainized stoneware tiles containing no waste suggest a good compatibility between the ceramic body and the waste that does not significantly change the properties of the final products and the conditions of the firing cycle. Nevertheless, the porosity increase, proportional to the waste content, causes a decrease in density, shrinkage, spot resistance and whiteness. (C) 2002 Elsevier Science Ltd. All rights reserved.


2002 - Valorizzazione di rifiuti inorganici nel settore ceramico [Relazione in Atti di Convegno]
F.ANDREOLA; L.BARBIERI; A.CORRADI; I.LANCELLOTTI; M. ROMAGNOLI
abstract

Valorizzazione di rifiuti inorganici nel settore ceramico


2002 - Zeta potential and rheological behaviour of aqueous kaolin suspensions dispersed with sodium hexametaphosphate [Capitolo/Saggio]
Andreola, F.; Castellini, E.; Romagnoli, M.; Olhero, S. M.; Ferreria, J. M. F.
abstract

Deflocculants adsorb on particles' surfaces, increase the repulsive forces among them, reducing viscosity, while the soluble salts have an opposite effect on viscosity. This work studies the influence of deflocculant and salt concentration on zeta potential and correlates the results with rheological measurements.


2001 - Binary and ternary mixtures of deflocculating additives for whitewares slurries. [Relazione in Atti di Convegno]
F. ANDREOLA; M. ROMAGNOLI; G.C. PELLACANI
abstract

In the traditional ceramic field, during the wet grinding stage liquid mixtures of additives are commonly used to guarantee high so/ids content (65–72 wt%) and a viscosity low enough to allow the suspension's workability. These characteristics are indispensable for using the new technologies for wet grinding (cylindrical and conical continuous mills) that require only 3–4 h of milling and permit considerable productivity (20 t/h). This work reports a laboratory study on the rheological behavior of whiteware slurries added with binary and ternary deflocculant mixtures.


2001 - Comportamento Reologico di smalti ceramici: influenza della composizione e delle variabili di preparazione delle fritte [Relazione in Atti di Convegno]
F.ANDREOLA; M. ROMAGNOLI
abstract

Comportamento Reologico di smalti ceramici: influenza della composizione e delle variabili di preparazione delle fritte


2001 - La fluidità delle polveri ceramiche: metodi di misura e variabili che influenzano lo scorrimento [Relazione in Atti di Convegno]
F.ANDREOLA; M. ROMAGNOLI
abstract

ISBN-88-8138-097-8


2001 - Problematiche e prospettive di recupero ed utilizzo dei fanghi di levigatura del gres porcellanato [Articolo su rivista]
Andreola F.; Barbieri L.
abstract

-


2001 - Problematiche e prospettive di valorizzazione di scorie di inceneritore urbano nel settore ceramico [Articolo su rivista]
Andreola F.; Barbieri L.; Lancellotti I.
abstract

-


2001 - Recycling in the Italian ceramic tile factories [Capitolo/Saggio]
Andreola F.; Barbieri L.; Lancellotti I.; Manfredini T.
abstract

In the Italian reality the unfired and fired by-products are totally recycled in the manufacturing cycle, and only those residues coming from depuration processes (glaze sludges and exhausted lime) cause technological problems, being less useful for recycling. Statistical data of the produced quantities, treated and recycled, divided by categories, are shown. Furthermore, we analyze a new category of ceramic residue, polishing sludges, that owing to their chemical characteristics, are not recycled in the ceramic bodies. We propose to reuse them as secondary raw materials to obtain porous materials with insulating properties by controlled thermal treatments.


2001 - The possibility to recycle solid residues of the municipal waste incineration into a ceramic tile body [Articolo su rivista]
F. Andreola; L. Barbieri; A. Corradi; I. Lancellotti; T. Manfredini
abstract

The feasibility of utilising solid residues of the municipal wastes incineration such as grate (bottom) ash and electrofilter and sleeve filter fly ash, in combination with a porcelain stoneware body, in the preparation of tiles has been investigated. While the chemical, mineralogical, thermal and rheological characterisation of the waste raw materials carries out some problems arising by using fly ash, these seem to be overcome with the bottom ash. The introduction of up to 20 wt% of this powder into the ceramic body does not substantially change the mineralogical and thermal behaviour of the product.


2001 - Valorization of a steel plant fly ash in a CMAS glass-ceramic [Capitolo/Saggio]
L. BARBIERI; F. ANDREOLA; A. CORRADI; I. LANCELLOTTI
abstract

Stable and inert glasses in the SiO2-Al2O3-CaO-MgO glass-ceramic system were prepared by adding up to 10 wt% of a steel plant fly ash, and subsequently crystallized. Steel waste dust acts mainly on the optical and thermal properties, without modifying the devitrification mechanism. In particular, the role of structure modifiers Fe2O3 and ZnO, the main oxides present in the waste, is to lower the viscosity and refractoriness of the system. Iron, present mainly in tetrahedral coordination in a 3+ oxidation state, confers yellow-brown color to the glasses. As a consequence of heat treatment, pyroxenic glass-ceramics develop with a surface mechanism, as in the CMAS parent system. On the basis of a previous work, the effect of steel waste dust is reasonably comparable to that of pure iron oxide, with the advantage of using an inexpensive raw material with a good environmental impact factor.


2000 - Effetto di Additivi Chimici sulle Caratteristiche Reologiche di Sospensioni Ceramiche Tradizionali per Tape-Casting. [Relazione in Atti di Convegno]
F.ANDREOLA; E.CASTELLINI; M. ROMAGNOLI
abstract

Sono presentati i risultati di una sperimentazione che ha visto l'utilizzo di tre diverse tipologie di additivi su un impasto di tipo industriale e avente come intento l'individuazione di additivi che permettano, a parità di contenuto solido, di ridurre la viscosità della sospensione, attraverso una razionale serie di prove. Viene mostrato quali additivi o miscele permettono di ottenere i comportamenti reologici piu adeguati a tale tecnica di formatura. Parametri reologici quali la viscosità e la tissotropia delle sospensioni sono messi in relazionealla composizione degli additivi.


2000 - Glass-ceramics sintered by glassy powders of no hazardous special wastes [Articolo su rivista]
L. BARBIERI; A. CORRADI; I. LANCELLOTTI; T. MANFREDINI; F. ANDREOLA
abstract

An alternative method for recycling municipal incinerator grate ash is proposed. The glassy powder is sintered to obtain glass-ceramic materials. The results obtained from mineralogical, physical and microstructural analyses show that it is possible to obtain dense finished products consisting of common silicate crystalline phases (wollastonite, diopside) by firing treatments with shorter time and lower temperature with respect to bulk devitrification. 20 refs.


2000 - Microwave technology applied to the recycling of fine stoneware tiles polishing sludge compared to conventional firing [Articolo su rivista]
ANDREOLA; F.; LEONELLI; C.; SILIGARDI; C.; C. LEONELLI; BONAMARTINI CORRADI A.
abstract

Microwave technology was a useful heating process when applied to the recycling of fine stoneware tiles polishing sludge. The manufact processed were characterized by low porosity, much lower than that registered for the same formulation heated with conventional firing.The different microstructure has been explained by considering the selective heating phenomenon generated by microwave irradiation: the SiC particles could heat much faster that the aluminosilicate matrix so that to melt the surroundings with a sort of encapsulation process.Conventional heating lead to SiC reaction with oxygen promoting its conversion in CO2 thus creating large pores.


2000 - Optimization of fritting parameters of ceramic frits: effect on the rheological behavior of the glaze suspensions. [Articolo su rivista]
F. Andreola; E. Castellini; M. Romagnoli
abstract

Studies to optimize the prepn. parameters used in industrial frits are reported. Two frit compns. widely used for the prodn. of single-fired ceramic-glazes were chosen: an alk. boric and an earth-alk. boric compn. The chem. durability and rheol. behavior of the frit suspensions were studied in relation to changes in the fritting temp. and time. The results confirm that the two frits studied react differently to changes in fritting parameters due to the dependence on their chem. durability and compn. Suspensions prepd. with the alk.-boric frit displayed no significant change in their rheol. properties; the earth-alk.-boric frit suspensions were more markedly affected.


2000 - Optimization of fritting parameters of ceramic frits: effect on the rheological behaviour of the glaze suspensions [Articolo su rivista]
F. Andreola; E. Castellini; M. Romagnoli
abstract

Studies to optimize the preparation parameters used in industrial frits are reported. Two frit compositions widely used for the production of single-fired ceramic-glazes were chosen: an alkaline boric and an earth-alkaline boric composition. The chemical durability and rheological behavior of the frit suspensions were studied in relation to changes in the fritting temperature and time. The results confirm that the two frits studied react differently to changes in fritting parameters due to the dependence on their chemical durability and composition. Suspensions prepared with the alkaline-boric frit displayed no significant change in their rheological properties; the earth-alkaline-boric frit suspensions were more markedly affected.


2000 - Techniques used to determine porosity [Articolo su rivista]
F. Andreola; C. Leonelli; M. Romagnoli; P. Miselli
abstract

A comparison is made of the principal techniques (mercury porosimetry, helium pycnometry, image analysis and water absorption) that are used to measure porosity


2000 - Tecniche a confronto per la determinazione della porosità. Parte II [Articolo su rivista]
F. Andreola; C. Leonelli; M. Romagnoli; P. Miselli
abstract

Viene presentata I'applicazione delle tecniche presentate nella parte I a sei prodotti ceramici con diverse proprietà. Ogni tecnica utilizzata infatti risulta idonea per determinate classi di materiali; pertanto la scelta del procedimento di analisi viene fatta a seconda del tipo di risultato che si vuole ottenere. Lo scopo di tale lavoro e quello di evidenziare i vantaggi e gli svantaggi di ognuna a seconda del materiale sottoposto ad analisi.


2000 - The influence of additives on the rheological behavior of acqueous concentrated glaze suspensions. [Relazione in Atti di Convegno]
F.ANDREOLA; M. ROMAGNOLI; G.C. PELLACANI
abstract

Influenza di alcuni additivi chimici sul comportamento reologico di sospensioni di fritte ceramiche.


1999 - Dry glazing in ceramic tile production. [Relazione in Atti di Convegno]
Andreola, Nora Maria; Romagnoli, Marcello
abstract

The efficiency of four different methods used to measure the flowability of the powders has been studied. The results obtained on pigments used in the production of tiles were correlated with the data obtained in semi-industrial conditions.The influence of the powder moisture on the amount of pigment that falls on the tile's surface was evaluated.


1999 - Influence of the operative parameters on chemical durability and rheological behavior frits ceramic suspensions. [Relazione in Atti di Convegno]
F.ANDREOLA; D.BERNARDELLI; M. ROMAGNOLI; P.POZZI
abstract

Glaze application is the phase in a productive process that is more conditioned from the rheological properties of the glaze itself. During the preparation step in the mill, at moderately high temperatures (60-70°C), reactions between frits and the aqueous medium can occur and consequently begin the leaching of glassy network and the diffusion of the modifying ions through the leached frit layer. In the industrial process, variations on the pH and the ionic strength of glaze suspensions happen during the milling. Consequently changes on the rheological parameters (apparent viscosity, yield point, thixotropy) of glaze suspensions will verified. It is important to control these variables for keeping unaffected the aesthetic characteristics of the final products, after firing.


1999 - Reologìa de suspensiones de esmaltes cerámicos para monococción: estudio de la influencia de los aditivos utilizados. [Articolo su rivista]
F.ANDREOLA; P.POZZI; M. ROMAGNOLI
abstract

En este trabajo se presentan los resultados obtenidos a partir de la caracterización y el estudio del comportamiento reológico de suspensiones de fritas cerámicas para la elaboración de esmaltes para baldosas de monococión porosa.En particular se evidencian los efectos que los distintos componentes y aditivo, ejercen sobre los parámetros reológicos que oontrolan las fases de preparacion y de aplicación


1999 - Rheology of ceramics slurries with mixtures of deflocculanting agents. [Relazione in Atti di Convegno]
Andreola, Nora Maria; Castellini, Elena; Romagnoli, Marcello
abstract

In whiteware processing, as in most other technical processes involving concentrated suspensions, additives are used to decrease viscosity and control stability. Silicate, phosphate and polyacrylate sodium salts are the most used additives in the production of tiles, tablewares, sanitarywares etc. They are commercially available products with good deflocculant abilities and performance/costs ratio. The chemical action of each single component was studied1,2,3 but the authors are not aware of any studies on mixtures. The systems are complex because they are multi-phases and constituted by natural raw material. In the industrial field, liquid mixture of additives are generally used. They take an inferior amount of time before being active with respect to when they are used as solid salts and permit a better management in the plant.


1998 - Caratterizzazione di sospensioni acquose di fritte ceramiche additivate di materiali plastici [Relazione in Atti di Convegno]
F.ANDREOLA; P.POZZI; M. ROMAGNOLI
abstract

Caratterizzazione di sospensioni acquose di fritte ceramiche additivate di materiali plastici


1998 - Comparison Between poly(vynil acetate) and poly(vynil alcohol) as Binders for whiteware body composition. [Relazione in Atti di Convegno]
F.ANDREOLA; M. ROMAGNOLI; W. CARTY
abstract

Comparison Between poly(vynil acetate) and poly(vynil alcohol) as Binders for whiteware body composition to avoid spring-back phenomena during forming.


1998 - Rheological behavior of an STP deflocculated kaolin [Articolo su rivista]
Andreola F; Pozzi P; Neto JBR
abstract

Work attempts to characterize a physical chemical parameter responsible for fluctuations in the efficiency of STP's deflocculant ability in industrial use.


1998 - Rheological behavior of kaolin acqueous suspensions deflocculated with sodium tripolyphosphate at different ratio of crystalline phase [Articolo su rivista]
F.ANDREOLA; J.B.NIETO; P. POZZI
abstract

Rheological behavior of kaolin suspensions deflocculated with sodium tripolyphosphate at different ratio of crystalline phase


1998 - Utilizzo di scorie da inceneritore urbano nella produzione di gres porcellanato [Articolo su rivista]
F. ANDREOLA; L. BARBIERI; I. LANCELLOTTI; F. MAVRIDIS; P. POZZI
abstract

-


1997 - Impiego di carbossimetilcellulose come leganti negli smalti ceramici : studio del comportamento reologico [Relazione in Atti di Convegno]
F.ANDREOLA; R.LAPASIN; P.POZZI; M. ROMAGNOLI
abstract

Studio reologico dell'aggiunta di CMC in sospensioni di smalti ceramici per piastrelle.


1997 - Sintering and modification of porous structure caused by binder added to whiteware body composition [Relazione in Atti di Convegno]
Andreola, Nora Maria; Pozzi, Paolo; Romagnoli, Marcello
abstract

Study of the sintering of ceramic with use of organic binders


1997 - Sintering and modification of porous structure caused by binders added to whiteware body composition [Relazione in Atti di Convegno]
Andreola, Nora Maria; P., Pozzi; Romagnoli, Marcello
abstract

The behavior of 2 viscosity-grade polyvinyl alcohols. was studied at 2 different percentages added to the slurry used for the preparation of tableware by isostatic pressing. The modification of the porous structure, the apparent d., and the elimination of the binder were examined. Results obtained show that binders do not modify the reactions during the firing process. More evident differences are verifiable in the porosity of the green and fired bodies, according to their mol. wt. and concn. Porosity decreased until 350°C (200°C for the binder with high mol. wt.), while from 450°C (350°C high wt. binder) to 700°C it increased quickly. At higher temps., as an effect of sintering, porosity fell dramatically to <3% and residual porosity is concd. in large pores. Effect of mol. wt. is to det. a higher porosity using the binder with longer chain while the bulk d. is lower. The green body with higher percentage of adhesive presents a lower open porosity and bulk d.


1997 - Wet grinding ceramic frits: effects of the size of the grinding media, grinding time and solid content. [Articolo su rivista]
F.Andreola; P.Pozzi; M.Romagnoli
abstract

The effect of variables in the wet grinding process, such as the size of the grinding media, grinding time and solid content, was investigated using an aq. suspension of glassy frit, typically used for the prodn. of glazes in the manuf. of ceramic tiles. The aim was to examine the process parameters which will enable optimization of the grinding process for brittle materials. The frit was ground with three mill charges, formed of sintered alumina balls of different sizes, and the particle size dimensions were measured as a function of grinding time and of the amt. of solid content of the aq. suspensions. The results indicate that the mill charge ( ratio of grinding ball diams.), grinding times and solid content of the suspensions must be carefully controlled in order to optimize the grinding process. A lower limit of particle size dimensions, after very long grinding times, was obtained.


1997 - Zeolititi nazionali nella depurazione di acque reflue e loro successivo utilizzo in impasti ceramici [Articolo su rivista]
Andreola F.; Manfredini T.; Passaglia E.; Pellacani G.C
abstract

Vengono riportati i risultati di uno studio eseguito con lo scopo di valutare la capacità di una zeolite italiana nella depurazione di una soluzione contenente Pb, Ba e Zn ed il suo successivo utilizzo all'interno di imapsti ceramici per la produzione di piastrelle da pavimentazione.


1996 - Additives used in the pressing of tableware [Articolo su rivista]
Andreola F; Pozzi P; Romagnoli M; Bresciani A; Pasquali G
abstract

Binder monomer chain length and concentration affect the mechanical behavior of tableware during fabrication by isostatic pressing.


1996 - CONFRONTO TRA IL COMPORTAMENTO LEGANTE Dl ALCOOLPOLIVINILICI A DIVERSO PESO MOLECOLARE E ACETATO Dl POLIVINILE IN COMPOSIZIONI PER PIATTI A IMPASTO BIANCOOTTENUTI PER PRESSATURA ISOSTATICA [Articolo su rivista]
F. Andreola; P. Pozzi; M. Romagnoli; G. Pasquali; A. Bresciani
abstract

La pressatura isostatica, negli ultimi anni, e stata applicata con successo nella fabbricazione di refrattari e stoviglieria, può essere utilizzata nella fabbricazione di quasi tutte le forme di piatti e anche di articoli più complessi non simmetrici; tale procedimento tuttavia presenta il fenomeno della rapidaespansione del pezzo dopo la pressatura, con conseguente danneggiamento del manufatto. Al fine di evitare l'inconveniente si aggiungono all'impasto leganti in grado di opporsi all'espansione. Il lavoro qui riportato riferisce sui risultati ottenutidall'impiego di tre alcool polivinilici, aggiunti in tre diverse percentuali in barbottine utilizzate per la preparazione di piatti con la pressatura isostatica.


1996 - Comparison of the binding behavior of poly(vinyl alcohol) with varying molecular weight and poly(vinyl acetate) in compositions for white body plates obtained by isostatic pressing. [Articolo su rivista]
F.Andreola; P.Pozzi; M.Romagnoli; G.Pasquali; A.Bresciani
abstract

Over the past few years, the isostatic pressing method has been successfully applied for the prodn. of refractories and tableware. This method may be used for the prodn. of practically all shapes of plates, and also for more complex non-sym. pieces. This procedure leads to a rapid expansion of the piece after pressing, possibly resulting in damage. To avoid this problem, binding agents are added to the bodies which are capable of combating the expansion phenomenon. The effects of three types of poly(vinyl alc.) (varying mol. wt.), added in three different quantities, and poly(vinyl acetate) on this expansion phenomenon in the isostatic pressing of plates were examd.


1996 - Studio della tempo dipendenza in presenza di effetti irreversibili in sospensioni di fritte ceramiche [Relazione in Atti di Convegno]
F. ANDREOLA; R. LAPASIN; P.POZZI; M. ROMAGNOLI
abstract

Studio della tempo dipendenza in presenza di effetti irreversibili in sospensioni di fritte ceramiche


1995 - La depuracion y el reciclaje de residuos en la industria ceramica de baldosas [Articolo su rivista]
F. ANDREOLA; T.MANFREDINI; G.C.PELLACANI; P. POZZI
abstract

Studio dell'utilizzo di residui della depurazione di acque industriali in materiali ceramici


1995 - Microestructura y propriedades de baldosas de ares porcelanico obtenidas por monococcion rapida de una tipica pasta ceramica caolinitica [Articolo su rivista]
F.ANDREOLA; T.MANFREDINI; G.C.PELLACANI; M. ROMAGNOLI
abstract

Este estudio tiene como objetivo profundizar el conocimiento de la evoluciòn de la microestructura y correlarlas a las materias primas utilizadas; investigar las reacciones quìmicas entre los componentes presentes en las formulaciones de las pastas usadas para la producciòn de grès porcelànico y en particular los efectos de los materiales caolìniticos en el desarrollo de la microestructura del producto durante la cocciòn.


1995 - Recycling of Ceramic wastes to reduce pollution [Articolo su rivista]
F. Andreola; T. Manfredini; G.C. Pellacani; P. Pozzi; M. Romagnoli
abstract

Exhausted limes and sludges (containing prevalently glass frits and glaze components), are waste substances to be eliminated. Recycling of about 0.10-0.15 wt% of exhausted lime and about 0.50 wt% of glass frits permits their complete elimination without affecting the industrial process. Release tests demonstrate as the firing process acts in the inertization of soluble heavy-metals ions.


1995 - Reologia di sospensioni acquose di argille deflocculate con TPF a differenti fasi cristalline [Relazione in Atti di Convegno]
F.ANDREOLA; P.POZZI; M. ROMAGNOLI
abstract

Reologia di sospensioni acquose di argilla deflocculate con tripolifosfato di sodio a differenti fasi cristalline.


1994 - CONCENTRATED GLAZE SUSPENSIONS [Articolo su rivista]
ANDREOLA F; CORRADI AB; MANFREDINI T; PELLACANI GC; POZZI P
abstract

The effect of grinding time, solid slip content, kaolin plasticizer and Ca2+ flocculating agent on the rheological behavior of a typical industrial frit used in glazes for monoporosa wall tile are described.


1994 - Rheological behaviour of aqueous concentrated suspensions of an Italian zeolite [Articolo su rivista]
F.ANDREOLA; T.MANFREDINI; G.C.PELLACANI; P. POZZI; M. ROMAGNOLI
abstract

The paper reports a laboratory study on the rheological behaviour of concentrated aqueous suspensions of zeolitite, belonging to the geological formations of «tufo giallo napoletano» in the Phlegraean Fields (Campania). Rheological measurement performed by means of a rotational viscometer demonstrated how the suspensions show a practically newtonian behaviour up to about 40 wtOfo of solid content in absence of deflocculants and up to about SO wtOfo of solid content in presence of Na-SIL and Na-TPP detlocculants. At higher solid concentrations they assume a non-newtonian behaviour. Na-TPP shows a greater deflocculating ability toward zeolite suspensions than Na-SIL. This may be explained by considering, in particular, its sequestering action towards the flocculating ions.


1994 - Utilization of an Italian zeolitite in ceramic bodies [Articolo su rivista]
Andreola F.; Manfredini T.; Passaglia E.; Pellacani G.C; Pozzi P.; Romagnoli M.
abstract

UTILIZATION OF ITALIAN ZEOLITITE IN CERAMIC BODIESThe papers reports a laboratory and industrial study on the possibility of using an Italian natural zeolitite, both in natural and Pb-; Ba- exchanged form, in a tile ceramic body. Because of their exchangeable cation contents (Na+, K+; Ca+2, Ba+2, Pb+2), natural and exchanged zeolitites can be added (up to 20 and 5wt%, respectively) in a ceramic body, thus favouring its sinterability and unaffecting the crystalline phase formation and the final products characteristics. The addition of higher amounts enhaces the swelling of the tiles during firing and strongly modifies the features of the fired tiles. Release tests in acetic and nitric acid solutions on unfired and fired tiles containing exchanged zeolitites demostrated the inertization of lecheable Pb+2 during firing.


1993 - Addition of exhausted lime in ceramic bodies: possibilities for an environmentally compatible tile production [Articolo su rivista]
N.M.F. Andreola; L.Bonfatti; T.Manfredini; G.C.Pellacani; P.Pozzi; M.Romagnoli
abstract

Pollution caused by inorganic wastes in the traditional ceramics industry is minimised by utilising exhausted limes, which are the byproducts in bag filters after the purification of flue gases in wet tile production. This study determined which quantities of exhausted lime added to tile bodies did not significantly affect the physico-chemical properties of the slips (i.e. density /viscosity/deflocculant amount) during wet grinding in ball mills. The results demonstrated that these conditions are obtained when exhausted lime in the bodies does not exceed 0.10 to 0.12 mass%. Furthermore, any increase in fluorine emission in the firing of tiles with exhausted lime can be trapped in the bag filters by increasing the lime content by about 10 mass%. The laboratory and industrial results are also compared.


1993 - Addition of exhausted lime in ceramic bodies: possibilities for an environmentally compatible tile production III: Industrial Results [Articolo su rivista]
F.ANDREOLA; L.BONFATTI; T.MANFREDINI; G.C.PELLACANI; P. POZZI; M.ROMAGNOLI
abstract

study uses exhausted lime in ceramic


1993 - Recycling of ceramic wastes in tile bodies to reduce pollution [Articolo su rivista]
F.ANDREOLA; T.MANFREDINI; G.C.PELLACANI; P. POZZI; M.ROMAGNOLI
abstract

During recent years, special attention has been devoted both to solving pollution problems during the manufacturing of ceramics and to learning how ceramics can themselves be a solution. Waste encapsulation opportunities for structural clay products have been studied. These opportunities affect environmental isolation within the semivitreous matrix of the product and remove and destroy volatile organic components of the waste and recrystallized incinerator slags and encapsulant for such heavy metals as lead. To reduce hazards to workers and community and to realize a safe environment, some manufacturers have planned for a production process that recycles wastes. This plan represents the best option to reduce or minimize pollution by permitting the complete elimination of wastes and thus avoiding their very expensive storage in appropriate dumps. Studies have been performed to evaluate the effects of the presence of exhausted lime and sludges in tile bodies and to obtain information for the rationalization of the recycling process. The focus has been on the evaluation of the effects of the presence of wastes on the rheological and thermal behavior of the tile bodies. In addition, the efficiency of the firing process on the wastes and heavy-metals inertization has been determined by release tests of the fired products in different acidic media.


1993 - Reuse of waste lime in a ceramic body that generated it. [Articolo su rivista]
F.Andreola; T.Manfredini; M.Romagnoli
abstract

Results are presented from studies of the effect of addns. of waste lime on the rheol. behavior of tile-body slips, the dilatometric behavior of tile bodies, water absorption and shrinkage of fired tiles, and the tile microstructure development during firing. A <0.1 wt.% addn. of waste lime had negligible effect on the apparent viscosity of slips, and an .apprx.0.5 wt.% addn. did not product significant changes in the microstructure. Control of F emissions due to recycling of the CaF2-contg. waste lime is discussed.


1992 - Addition of exhausted lime in ceramic bodies:possibilities for an environmentally compatible tile production II:thermal behaviour of bodies [Articolo su rivista]
N.M.F.ANDREOLA; L.BONFATTI; T.MANFREDINI; G.C.PELLACANI; P. POZZI
abstract

study uses exhausted lime in ceramic


1992 - Reactivity of CaF2 Toward Components of Ceramic Bodies. [Relazione in Atti di Convegno]
Andreola N. M.; Manfredini T. ; Pellacani G.C.; Romagnoli M.
abstract

The production of ceramic tiles results in the expulsion of many wastes. One of the waste substances which could be eliminated from the tile-making process is the exhausted lime which contains calcium fluoride as the main component. The maximum amount of exhausted lime which can be recycled without modifying the properties of the tiles is determined. The effects of the calcium fluoride on the microstructure of the tiles is investigated. It is discovered that addition of CaF2 greater than 0.5-1.0 wt% results in a strongly modified microstructure. Anorthite is produced at the expense of mullite leading to swelling of the tiles at the industrial firing temperatures.


1992 - addition of exhausted lime in ceramic bodies: possibilities for an environmentally compatible tile production I: rheological of slips [Articolo su rivista]
N.M.ANDREOLA; L.BONFATTI; T.MANFREDINI; G.C.PELLACANI; P. POZZI
abstract

study of the rheology of ceramic suspension with recicling material presence