The Experts below are selected from a list of 1185 Experts worldwide ranked by ideXlab platform
Angelo Tartaglia - One of the best experts on this subject based on the ideXlab platform.
-
thermal decomposition of asbestos and recycling in Traditional Ceramics
Journal of The European Ceramic Society, 2000Co-Authors: Alessandro F Gualtieri, Angelo TartagliaAbstract:Abstract Given the known carcinogenic effects, its wide occupational exposures and widespread use in the past, asbestos is considered a general health hazard and a priority treatment for pollution prevention. In this context, asbestos can be entirely transformed to a mixture of non hazardous silicate phases throughout a thermal treatment at 1000–1250°C and to a silicate glass at T >1250°C. These products may be recycled for the production of Traditional Ceramics. In this paper we describe the recycle of thermally treated asbestos containing materials as a raw material for glass Ceramics and Traditional Ceramics. A significant improvement of the technological properties of porcelainised stoneware, obtained by high sintering of unglazed ceramic bodies, is accomplished by the addition of 5 wt% of an asbestos-based glass ceramic.
-
Thermal decomposition of asbestos and recycling in Traditional Ceramics
Journal of the European Ceramic Society, 2000Co-Authors: Alessandro F Gualtieri, Angelo TartagliaAbstract:Given the known carcinogenic effects, its wide occupational exposures and widespread use in the past, asbestos is considered a general health hazard and a priority treatment for pollution prevention. In this context, asbestos can be entirely transformed to a mixture of non hazardous silicate phases throughout a thermal treatment at 1000-1250??C and to a silicate glass at T > 1250??C. These products may be recycled for the production of Traditional Ceramics. In this paper we describe the recycle of thermally treated asbestos containing materials as a raw material for glass Ceramics and Traditional Ceramics. A significant improvement of the technological properties of porcelainised stoneware, obtained by high sintering of unglazed ceramic bodies, is accomplished by the addition of 5 wt% of an asbestos-based glass ceramic. (C) 2000 Elsevier Science Ltd. All rights reserved.
Alessandro F Gualtieri - One of the best experts on this subject based on the ideXlab platform.
-
thermal decomposition of asbestos and recycling in Traditional Ceramics
Journal of The European Ceramic Society, 2000Co-Authors: Alessandro F Gualtieri, Angelo TartagliaAbstract:Abstract Given the known carcinogenic effects, its wide occupational exposures and widespread use in the past, asbestos is considered a general health hazard and a priority treatment for pollution prevention. In this context, asbestos can be entirely transformed to a mixture of non hazardous silicate phases throughout a thermal treatment at 1000–1250°C and to a silicate glass at T >1250°C. These products may be recycled for the production of Traditional Ceramics. In this paper we describe the recycle of thermally treated asbestos containing materials as a raw material for glass Ceramics and Traditional Ceramics. A significant improvement of the technological properties of porcelainised stoneware, obtained by high sintering of unglazed ceramic bodies, is accomplished by the addition of 5 wt% of an asbestos-based glass ceramic.
-
Thermal decomposition of asbestos and recycling in Traditional Ceramics
Journal of the European Ceramic Society, 2000Co-Authors: Alessandro F Gualtieri, Angelo TartagliaAbstract:Given the known carcinogenic effects, its wide occupational exposures and widespread use in the past, asbestos is considered a general health hazard and a priority treatment for pollution prevention. In this context, asbestos can be entirely transformed to a mixture of non hazardous silicate phases throughout a thermal treatment at 1000-1250??C and to a silicate glass at T > 1250??C. These products may be recycled for the production of Traditional Ceramics. In this paper we describe the recycle of thermally treated asbestos containing materials as a raw material for glass Ceramics and Traditional Ceramics. A significant improvement of the technological properties of porcelainised stoneware, obtained by high sintering of unglazed ceramic bodies, is accomplished by the addition of 5 wt% of an asbestos-based glass ceramic. (C) 2000 Elsevier Science Ltd. All rights reserved.
G N Angelopoulos - One of the best experts on this subject based on the ideXlab platform.
-
thermal behaviour of clays for Traditional Ceramics with soda lime silica waste glass admixture
Journal of The European Ceramic Society, 2007Co-Authors: Yiannis Pontikes, L Esposito, A Tucci, G N AngelopoulosAbstract:Abstract The thermal behaviour of clay body mixtures with soda–lime–silica waste glass for the production of Traditional Ceramics was assessed. The effect of calcite content in the body mixture, of the particle size distribution of glass and of the firing temperature was investigated. In the case of calcite-rich mixtures with glass, increased expansion may take place during firing, at temperatures slightly higher than 700 °C. This effect is attributed to the entrapment of released gases, mainly CO 2 . Sintering starts at lower temperatures for the samples with glass, whereas, a second shrinkage zone was observed for temperatures approaching 1000 °C. The content of calcite is one of the main factors determining the mineralogy of the sintered body and the extent of glass devitrification. Devitrite, cristobalite and wollastonite are the products of devitrification within the glass grains, whereas, sodium aluminum silicate, most probably nepheline, has been formed at the inter-granular rim, between glass and ceramic matrix. Increase in the firing temperature and/or decrease in the particle size distribution of glass promotes the densification of the body.
-
Thermal behaviour of clays for Traditional Ceramics with soda–lime–silica waste glass admixture
Journal of The European Ceramic Society, 2006Co-Authors: Yiannis Pontikes, L Esposito, A Tucci, G N AngelopoulosAbstract:Abstract The thermal behaviour of clay body mixtures with soda–lime–silica waste glass for the production of Traditional Ceramics was assessed. The effect of calcite content in the body mixture, of the particle size distribution of glass and of the firing temperature was investigated. In the case of calcite-rich mixtures with glass, increased expansion may take place during firing, at temperatures slightly higher than 700 °C. This effect is attributed to the entrapment of released gases, mainly CO 2 . Sintering starts at lower temperatures for the samples with glass, whereas, a second shrinkage zone was observed for temperatures approaching 1000 °C. The content of calcite is one of the main factors determining the mineralogy of the sintered body and the extent of glass devitrification. Devitrite, cristobalite and wollastonite are the products of devitrification within the glass grains, whereas, sodium aluminum silicate, most probably nepheline, has been formed at the inter-granular rim, between glass and ceramic matrix. Increase in the firing temperature and/or decrease in the particle size distribution of glass promotes the densification of the body.
-
use of scrap soda lime silica glass in Traditional Ceramics
Glass Technology, 2005Co-Authors: Yiannis Pontikes, L Esposito, G N Angelopoulos, Angeliki Christogerou, E Rambaldi, A TucciAbstract:A Iternatives ways of recycling soda-lime-silica scrap glass (SLS) glass, apart from remelting can offer certain advantages and may be implemented when glass production is not suitable. For the Ceramics industry, the incorporation of glass into the ceramic body may improve the quality of fired products and save energy. Mixtures of SLS glass and ceramic raw materials used for the production of porcelain stoneware tiles and heavy-clay products were developed and examined. In the case of porcelain stoneware tiles, several modified mixes were prepared by replacing different amounts of the fluxing component, sodium feldspathic sand. For roofing tiles, SLS glass was added at a fixed percentage in the body mixes. The fired samples were characterised in terms of linear shrinkage, water absorption, flexural strength and reliabilit Microstructure and the main phase transformations in the fired samples were examined by x-ray diffraction and by scanning electron microscopy along with EDS microanalysis. The results, for the porcelain stoneware body mix, show that a substitution of the fluxing component in the range of 5-10 wt% is feasible. The new formulations had lower water absorptions, adequate flexural strengths and a consistent increase in reliability due to improved homogeneity. For substitutions exceeding 10 wt%, plagioclase was crystallised, which inhibited the formation of mullite and did not favour densification. The results regarding the modified body mix for heavy clay products have shown that a glass additions up to 30 wt% are feasible. New crystalline phases were developed within and at the interface of the glass grains. The particle size distribution of the glass and the firing temperature both influenced the physical and mechanical characteristics whereas they had a minor effect on the mineralogy. The fired products demonstrated improved characteristics in terms of water absorption and bending strength.
G Silva - One of the best experts on this subject based on the ideXlab platform.
-
thermal conductivity of Traditional Ceramics part ii influence of mineralogical composition
Ceramics International, 2010Co-Authors: J Garciaten, M J Orts, A Saburit, G SilvaAbstract:Abstract The thermal conductivity of Traditional ceramic materials is known to be a function of their porosity or bulk density. However, the scatter in the thermal conductivity–bulk density data in certain studies, particularly when data from industrially processed brick are involved, suggests that thermal conductivity depends, apart from porosity, on other characteristics such as mineralogical composition, microstructure, humidity, and the presence of soluble salts. A standard red-firing clay used in brick manufacture has been used in this study with a view to systematising the impact of the different variables that could influence thermal conductivity and mechanical strength. Part I of the study presented the results obtained when the dry bulk density of the pieces and their firing temperature were modified. Part II examines the influence of the mineralogical composition of the starting raw materials mixture on the thermal conductivity and mechanical strength of clay brick products. The findings suggest that to manufacture Traditional Ceramics with high thermal insulation and appropriate mechanical properties, it is advisable to use illitic-kaolinitic clays. Large-sized potassium feldspar and quartz particles adversely affect fired mechanical strength. In addition, quartz has high thermal conductivity. The addition of carbonates or the use of calcareous clays has a positive effect on mechanical strength, because carbonate acts as a pore-forming agent and generates crystalline phases during firing that enhance mechanical strength.
-
thermal conductivity of Traditional Ceramics part i influence of bulk density and firing temperature
Ceramics International, 2010Co-Authors: M J Orts, A Saburit, G SilvaAbstract:Abstract The thermal conductivity of Traditional Ceramics is known to be a function of their porosity or bulk density. However, the scatter in the thermal conductivity–bulk density data in certain studies, particularly when data from industrially processed brick are involved, suggests that thermal conductivity depends, apart from porosity, on other characteristics such as phase composition, microstructure, humidity or the presence of soluble salts. A red-firing clay used in brick manufacture has been used in this study with a view to systematising the impact of the different variables that could influence thermal conductivity and mechanical strength. This first paper presents the results obtained when the dry bulk density of the pieces and their firing temperature were modified. It was confirmed that thermal conductivity did not solely depend on the total porosity of the fired pieces, but that pore size distribution and pore interconnectivity need to be considered, which depend on the degree of firing attained, and may also be influenced by the phases present in the pieces, whose content and/or composition could vary with firing temperature.
Gian Carlo Pellacani - One of the best experts on this subject based on the ideXlab platform.
-
microwave thermal inertisation of asbestos containing waste and its recycling in Traditional Ceramics
Journal of Hazardous Materials, 2006Co-Authors: Cristina Leonelli, M. R. Rivasi, D. Rabitti, D N Boccaccini, Fernanda Andreola, Paolo Veronesi, Isabella Lancellotti, Luisa Barbieri, Gian Carlo PellacaniAbstract: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.
-
Microwave thermal inertisation of asbestos containing waste and its recycling in Traditional Ceramics
Journal of Hazardous Materials, 2006Co-Authors: Cristina Leonelli, M. R. Rivasi, D. Rabitti, D N Boccaccini, Fernanda Andreola, Paolo Veronesi, Isabella Lancellotti, Luisa Barbieri, Gian Carlo PellacaniAbstract: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. © 2005 Elsevier B.V. All rights reserved.