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Alessandro F Gualtieri - One of the best experts on this subject based on the ideXlab platform.
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Crystal chemistry of the high temperature product of transformation of cement-asbestos
Journal of Hazardous Materials, 2013Co-Authors: Alberto Viani, Alessandro Croce, Alessandro F Gualtieri, Simone Pollastri, Caterina Rinaudo, Giulia D'ursoAbstract:In this work, the high-temperature inertization product of a representative batch of samples of cement-asbestos (CA) from different localities in Italy have been characterized with a multidisciplinary approach. All the Raw CA samples were heated at 1200 ??C for 15. min. After firing, they underwent a series of solid state reactions leading to global structural changes of the matrix. Effects of annealing time and temperature on the crystallization kinetics were thoroughly investigated. Both factors acted in favour of equilibrium. Three classes of CA were identified with the aid of phase diagrams and of specific plots relating chemical and mineralogical parameters. This result was considered of importance in view of the potential use of transformed cement-asbestos as a Secondary Raw Material. In principle, the content of CA packages removed from the environment and their corresponding heat-treated products can be classified simply using XRF. This method allows for the selection of appropriate fractions in function of the most suitable recycling solution adopted. Samples belonging to the class called larnite-rich, turned out to be of great interest as possible candidate for substituting a fraction of cement in many building Materials and innovative green cement productions. ?? 2012 Elsevier B.V.
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Recycling the product of thermal transformation of cement-asbestos for the preparation of calcium sulfoaluminate clinker
Journal of Hazardous Materials, 2013Co-Authors: Alberto Viani, Alessandro F GualtieriAbstract:According to recent resolutions of the European Parliament (2012/2065(INI)), the need for environmentally friendly alternative solutions to landfill disposal of hazardous wastes, such as asbestos-containing Materials, prompts their recycling as Secondary Raw Materials (end of waste concept). In this respect, for the first time, we report the recycling of the high temperature product of cement-asbestos, in the formulation of calcium sulfoaluminate cement clinkers (novel cementitious binders designed to reduce CO2 emissions), as a continuation of a previous work on their systematic characterization. Up to 29wt% of the Secondary Raw Material was successfully introduced into the Raw mix. Different clinker samples were obtained at 1250°C and 1300°C, reproducing the phase composition of industrial analogues. As an alternative source of Ca and Si, this Secondary Raw Material allows for a reduction of the CO2 emissions in cement production, mitigating the ecological impact of cement manufacturing, and reducing the need for natural resources. © 2013 Elsevier B.V.
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in vitro biodurability of the product of thermal transformation of cement asbestos
Journal of Hazardous Materials, 2012Co-Authors: Alessandro F Gualtieri, Giulia Sgarbi, Alberto Viani, Gigliola LusvardiAbstract:Abstract To safely recycle the product of the thermal transformation of cement–asbestos as Secondary Raw Material, its toxicity potential should be assessed by in vitro biodurability tests. In this work, the acellular in vitro biodurability of the products of transformation of cement–asbestos at 1200 °C (named KRY·AS) was tested using both inorganic and organic simulated lung fluids at pH 4.5. The dissolution kinetics were followed using chemical, mineralogical and microstructural analyses. The total dissolution time estimated from the experiments with inorganic HCl diluted solution is one order of magnitude higher than that determined from the experiments with buffered Gamble solution (253 days vs. 20 days). The key parameter determining the difference in dissolution rate turns out to be the solidus/liquidus ratio which prompts a fast saturation of the solution with monosilicic acid. The calculated dissolution rate constants showed that the biodurability in vitro of KRY·AS is much lower with respect to that of standard chrysotile asbestos (total estimated dissolution time of 20 days vs. 298 days, respectively). This proves a low potential toxicity of this Secondary Raw Material.
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In vitro biodurability of the product of thermal transformation of cement–asbestos
Journal of Hazardous Materials, 2012Co-Authors: Alessandro F Gualtieri, Giulia Sgarbi, Alberto Viani, Gigliola LusvardiAbstract:Abstract To safely recycle the product of the thermal transformation of cement–asbestos as Secondary Raw Material, its toxicity potential should be assessed by in vitro biodurability tests. In this work, the acellular in vitro biodurability of the products of transformation of cement–asbestos at 1200 °C (named KRY·AS) was tested using both inorganic and organic simulated lung fluids at pH 4.5. The dissolution kinetics were followed using chemical, mineralogical and microstructural analyses. The total dissolution time estimated from the experiments with inorganic HCl diluted solution is one order of magnitude higher than that determined from the experiments with buffered Gamble solution (253 days vs. 20 days). The key parameter determining the difference in dissolution rate turns out to be the solidus/liquidus ratio which prompts a fast saturation of the solution with monosilicic acid. The calculated dissolution rate constants showed that the biodurability in vitro of KRY·AS is much lower with respect to that of standard chrysotile asbestos (total estimated dissolution time of 20 days vs. 298 days, respectively). This proves a low potential toxicity of this Secondary Raw Material.
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Structural and spectroscopic characterization of anorthite synthesized from Secondary Raw Materials
Periodico Di Mineralogia, 2011Co-Authors: Alessandro F Gualtieri, Carlotta Giacobbe, Gigliola Lusvardi, Giovanni B Andreozzi, Cecilia VitiAbstract:Periodico di Mineralogia (2011), 80, 2, 247-266 - DOI:10.2451/2011 PM0018 Structural and spectroscopic characterization of anorthite synthesized from Secondary Raw Materials Alessandro Francesco Gualtieri 1,* , Giovanni B. Andreozzi 2 , Carlotta Giacobbe 1 , Gigliola Lusvardi 3 and Cecilia Viti 4 1 Dipartimento di Scienze della Terra, University of Modena and Reggio Emilia, Italy 2 Dipartimento di Scienze della Terra, Sapienza University of Rome, Italy 3 Dipartimento di Chimica, University of Modena and Reggio Emilia, Italy 4 Dipartimento di Scienze della Terra, University of Siena, Italy * Corresponding author: alessandro.gualtieri@unimore.it Abstract Recycling of Secondary Raw Materials is a priority of waste handling in the countries of the European community. A virtual Secondary Raw Material of great importance is the product of the thermal transformation of cement - asbestos. This work illustrates the study of calcination products obtained starting from the product of the thermal transformation of cement-asbestos at 1200 °C, added to primary Raw Materials (kaolin, aluminum hydroxide) and boric acid as mineralizing agent. The calcination has been conducted at 1200 °C for 1 hour. The crystallization kinetics has been monitored using in situ high temperature X-ray powder diffraction. The microscopic characterization of the final product of calcination has been conducted with SEM and TEM imaging supported by X-ray microanalysis. The structure refinement was conducted on the powder sample using the Rietveld method. The results are compared with the spectroscopic characterization including Mossbauer and UV-Vis spectroscopies. The final product of the calcination is essentially anorthite (about 89 wt%) with minor spinel (11 wt%). All experimental data converge to support the hypothesis that the anorthite is stoichiometric, and the small amounts of iron detected (1.32 wt%) is Fe 3+ hosted in the structure of spinel. Key Words : Anorthite; synthesis; KRY·AS; Rietveld refinement; Fe-spinel.
Gigliola Lusvardi - One of the best experts on this subject based on the ideXlab platform.
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In vitro biodurability of the product of thermal transformation of cement–asbestos
Journal of Hazardous Materials, 2012Co-Authors: Alessandro F Gualtieri, Giulia Sgarbi, Alberto Viani, Gigliola LusvardiAbstract:Abstract To safely recycle the product of the thermal transformation of cement–asbestos as Secondary Raw Material, its toxicity potential should be assessed by in vitro biodurability tests. In this work, the acellular in vitro biodurability of the products of transformation of cement–asbestos at 1200 °C (named KRY·AS) was tested using both inorganic and organic simulated lung fluids at pH 4.5. The dissolution kinetics were followed using chemical, mineralogical and microstructural analyses. The total dissolution time estimated from the experiments with inorganic HCl diluted solution is one order of magnitude higher than that determined from the experiments with buffered Gamble solution (253 days vs. 20 days). The key parameter determining the difference in dissolution rate turns out to be the solidus/liquidus ratio which prompts a fast saturation of the solution with monosilicic acid. The calculated dissolution rate constants showed that the biodurability in vitro of KRY·AS is much lower with respect to that of standard chrysotile asbestos (total estimated dissolution time of 20 days vs. 298 days, respectively). This proves a low potential toxicity of this Secondary Raw Material.
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in vitro biodurability of the product of thermal transformation of cement asbestos
Journal of Hazardous Materials, 2012Co-Authors: Alessandro F Gualtieri, Giulia Sgarbi, Alberto Viani, Gigliola LusvardiAbstract:Abstract To safely recycle the product of the thermal transformation of cement–asbestos as Secondary Raw Material, its toxicity potential should be assessed by in vitro biodurability tests. In this work, the acellular in vitro biodurability of the products of transformation of cement–asbestos at 1200 °C (named KRY·AS) was tested using both inorganic and organic simulated lung fluids at pH 4.5. The dissolution kinetics were followed using chemical, mineralogical and microstructural analyses. The total dissolution time estimated from the experiments with inorganic HCl diluted solution is one order of magnitude higher than that determined from the experiments with buffered Gamble solution (253 days vs. 20 days). The key parameter determining the difference in dissolution rate turns out to be the solidus/liquidus ratio which prompts a fast saturation of the solution with monosilicic acid. The calculated dissolution rate constants showed that the biodurability in vitro of KRY·AS is much lower with respect to that of standard chrysotile asbestos (total estimated dissolution time of 20 days vs. 298 days, respectively). This proves a low potential toxicity of this Secondary Raw Material.
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Structural and spectroscopic characterization of anorthite synthesized from Secondary Raw Materials
Periodico Di Mineralogia, 2011Co-Authors: Alessandro F Gualtieri, Carlotta Giacobbe, Gigliola Lusvardi, Giovanni B Andreozzi, Cecilia VitiAbstract:Periodico di Mineralogia (2011), 80, 2, 247-266 - DOI:10.2451/2011 PM0018 Structural and spectroscopic characterization of anorthite synthesized from Secondary Raw Materials Alessandro Francesco Gualtieri 1,* , Giovanni B. Andreozzi 2 , Carlotta Giacobbe 1 , Gigliola Lusvardi 3 and Cecilia Viti 4 1 Dipartimento di Scienze della Terra, University of Modena and Reggio Emilia, Italy 2 Dipartimento di Scienze della Terra, Sapienza University of Rome, Italy 3 Dipartimento di Chimica, University of Modena and Reggio Emilia, Italy 4 Dipartimento di Scienze della Terra, University of Siena, Italy * Corresponding author: alessandro.gualtieri@unimore.it Abstract Recycling of Secondary Raw Materials is a priority of waste handling in the countries of the European community. A virtual Secondary Raw Material of great importance is the product of the thermal transformation of cement - asbestos. This work illustrates the study of calcination products obtained starting from the product of the thermal transformation of cement-asbestos at 1200 °C, added to primary Raw Materials (kaolin, aluminum hydroxide) and boric acid as mineralizing agent. The calcination has been conducted at 1200 °C for 1 hour. The crystallization kinetics has been monitored using in situ high temperature X-ray powder diffraction. The microscopic characterization of the final product of calcination has been conducted with SEM and TEM imaging supported by X-ray microanalysis. The structure refinement was conducted on the powder sample using the Rietveld method. The results are compared with the spectroscopic characterization including Mossbauer and UV-Vis spectroscopies. The final product of the calcination is essentially anorthite (about 89 wt%) with minor spinel (11 wt%). All experimental data converge to support the hypothesis that the anorthite is stoichiometric, and the small amounts of iron detected (1.32 wt%) is Fe 3+ hosted in the structure of spinel. Key Words : Anorthite; synthesis; KRY·AS; Rietveld refinement; Fe-spinel.
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Recycling of the product of thermal inertization of cement-asbestos for various industrial applications
Waste Management, 2011Co-Authors: Alessandro F Gualtieri, Carlotta Giacobbe, Lorenza Sardisco, Magdalena Lassinantti Gualtieri, Cinzia Cavenati, Martin Saraceno, Gigliola Lusvardi, Ivano ZanattoAbstract:Recycling of Secondary Raw Materials is a priority of waste handling in the countries of the European community. A potentially important Secondary Raw Material is the product of the thermal transformation of cement-asbestos, produced by prolonged annealing at 1200-1300 ??C. The product is chemically comparable to a Mg-rich clinker. Previous work has assured the reliability of the transformation process. The current challenge is to find potential applications as Secondary Raw Material. Recycling of thermally treated asbestos-containing Material (named KRY??AS) in traditional ceramics has already been studied with successful results.The results presented here are the outcome of a long termed project started in 2005 and devoted to the recycling of this Secondary Raw Materials in various industrial applications. KRY??AS can be added in medium-high percentages (10-40wt%) to commercial mixtures for the production of clay bricks, rock-wool glasses for insulation as well as Ca-based frits and glass-ceramics for the production of ceramic tiles. The Secondary Raw Material was also used for the synthesis of two ceramic pigments; a green uvarovite-based pigment [Ca3Cr2(SiO4)3] and a pink malayaite-based pigment [Ca(Sn,Cr)SiO5]. The latter is especially interesting as a substitute for cadmium-based pigments. This work also shows that KRY??AS can replace standard fillers in polypropylene plastics without altering the properties of the final product. For each application, a description and relevant results are presented and discussed. ?? 2010 Elsevier Ltd.
Jeffrey Wagner - One of the best experts on this subject based on the ideXlab platform.
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Incentivizing Secondary Raw Material markets for sustainable waste management
Waste Management, 2017Co-Authors: Maximilian Schreck, Jeffrey WagnerAbstract:Notwithstanding several policy initiatives in many countries over a number of years, there remains a general sense that too much municipal solid waste is generated and that too much of the waste that is generated is landfilled. There is an emerging consensus that a sustainable approach to waste management requires further development of Secondary Raw Material markets. The purpose of this paper is to propose a theoretical economic model that focuses upon this stage of a sustainable waste management program and explores policy options that could motivate efficiency in Secondary Raw Material markets. In particular, we show how firm profit and social welfare optimizing objectives can be reconciled in a two-product market of waste management processes: landfilling and Material reclamation. Our results provide theoretical support for building out recent Circular Economy initiatives as well as for the relatively recent emergence of landfill mining as a means for procuring Secondary Raw Materials.
Alberto Viani - One of the best experts on this subject based on the ideXlab platform.
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Crystal chemistry of the high temperature product of transformation of cement-asbestos
Journal of Hazardous Materials, 2013Co-Authors: Alberto Viani, Alessandro Croce, Alessandro F Gualtieri, Simone Pollastri, Caterina Rinaudo, Giulia D'ursoAbstract:In this work, the high-temperature inertization product of a representative batch of samples of cement-asbestos (CA) from different localities in Italy have been characterized with a multidisciplinary approach. All the Raw CA samples were heated at 1200 ??C for 15. min. After firing, they underwent a series of solid state reactions leading to global structural changes of the matrix. Effects of annealing time and temperature on the crystallization kinetics were thoroughly investigated. Both factors acted in favour of equilibrium. Three classes of CA were identified with the aid of phase diagrams and of specific plots relating chemical and mineralogical parameters. This result was considered of importance in view of the potential use of transformed cement-asbestos as a Secondary Raw Material. In principle, the content of CA packages removed from the environment and their corresponding heat-treated products can be classified simply using XRF. This method allows for the selection of appropriate fractions in function of the most suitable recycling solution adopted. Samples belonging to the class called larnite-rich, turned out to be of great interest as possible candidate for substituting a fraction of cement in many building Materials and innovative green cement productions. ?? 2012 Elsevier B.V.
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Recycling the product of thermal transformation of cement-asbestos for the preparation of calcium sulfoaluminate clinker
Journal of Hazardous Materials, 2013Co-Authors: Alberto Viani, Alessandro F GualtieriAbstract:According to recent resolutions of the European Parliament (2012/2065(INI)), the need for environmentally friendly alternative solutions to landfill disposal of hazardous wastes, such as asbestos-containing Materials, prompts their recycling as Secondary Raw Materials (end of waste concept). In this respect, for the first time, we report the recycling of the high temperature product of cement-asbestos, in the formulation of calcium sulfoaluminate cement clinkers (novel cementitious binders designed to reduce CO2 emissions), as a continuation of a previous work on their systematic characterization. Up to 29wt% of the Secondary Raw Material was successfully introduced into the Raw mix. Different clinker samples were obtained at 1250°C and 1300°C, reproducing the phase composition of industrial analogues. As an alternative source of Ca and Si, this Secondary Raw Material allows for a reduction of the CO2 emissions in cement production, mitigating the ecological impact of cement manufacturing, and reducing the need for natural resources. © 2013 Elsevier B.V.
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in vitro biodurability of the product of thermal transformation of cement asbestos
Journal of Hazardous Materials, 2012Co-Authors: Alessandro F Gualtieri, Giulia Sgarbi, Alberto Viani, Gigliola LusvardiAbstract:Abstract To safely recycle the product of the thermal transformation of cement–asbestos as Secondary Raw Material, its toxicity potential should be assessed by in vitro biodurability tests. In this work, the acellular in vitro biodurability of the products of transformation of cement–asbestos at 1200 °C (named KRY·AS) was tested using both inorganic and organic simulated lung fluids at pH 4.5. The dissolution kinetics were followed using chemical, mineralogical and microstructural analyses. The total dissolution time estimated from the experiments with inorganic HCl diluted solution is one order of magnitude higher than that determined from the experiments with buffered Gamble solution (253 days vs. 20 days). The key parameter determining the difference in dissolution rate turns out to be the solidus/liquidus ratio which prompts a fast saturation of the solution with monosilicic acid. The calculated dissolution rate constants showed that the biodurability in vitro of KRY·AS is much lower with respect to that of standard chrysotile asbestos (total estimated dissolution time of 20 days vs. 298 days, respectively). This proves a low potential toxicity of this Secondary Raw Material.
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In vitro biodurability of the product of thermal transformation of cement–asbestos
Journal of Hazardous Materials, 2012Co-Authors: Alessandro F Gualtieri, Giulia Sgarbi, Alberto Viani, Gigliola LusvardiAbstract:Abstract To safely recycle the product of the thermal transformation of cement–asbestos as Secondary Raw Material, its toxicity potential should be assessed by in vitro biodurability tests. In this work, the acellular in vitro biodurability of the products of transformation of cement–asbestos at 1200 °C (named KRY·AS) was tested using both inorganic and organic simulated lung fluids at pH 4.5. The dissolution kinetics were followed using chemical, mineralogical and microstructural analyses. The total dissolution time estimated from the experiments with inorganic HCl diluted solution is one order of magnitude higher than that determined from the experiments with buffered Gamble solution (253 days vs. 20 days). The key parameter determining the difference in dissolution rate turns out to be the solidus/liquidus ratio which prompts a fast saturation of the solution with monosilicic acid. The calculated dissolution rate constants showed that the biodurability in vitro of KRY·AS is much lower with respect to that of standard chrysotile asbestos (total estimated dissolution time of 20 days vs. 298 days, respectively). This proves a low potential toxicity of this Secondary Raw Material.
Jose Ramon Jimenez - One of the best experts on this subject based on the ideXlab platform.
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Promotion of circular economy: steelwork dusts as Secondary Raw Material in conventional mortars
Environmental Science and Pollution Research, 2019Co-Authors: Angélica Lozano-lunar, Auxi Barbudo, Jose-maria Fernandez, Jose Ramon JimenezAbstract:Among the actions proposed by the European Union for the implementation of Circular Economy is the use of waste as a Secondary Raw Material (SRM). During the fusion of the scrap, a steel dust is generated, named electric arc furnace dust (EAFD). The EAFD is composed mainly of potentially leachable heavy metals and is classified as a “hazardous” waste. Worldwide, approximately 70% of EAFD is deposited in landfills, with a previous treatment through cement-based Materials to prevent the metals’ mobility. However, this action is not in accordance with the Circular Economy concept. The present investigation analyses the use of EAFD as SRM in conventional mortar production for its use as a construction Material. Different substitution percentages (25, 50 and 100%) were used replacing the siliceous filler by EAFD. A preceding characterisation of the waste by X-ray fluorescence, X-ray diffraction, specific surface area, bulk density, electron microscopy and particle size distribution was performed. The investigation analysed the behaviour of conventional mortars by tests of workability, compressive strength, mineralogy, water absorption by capillarity, and leaching behaviour in granular and monolithic states. The results obtained indicate a slight improvement in mechanical behaviour with the incorporation of EAFD, the reason why its use as SRM in conventional mortars would benefit the construction industry and would encourage the Circular Economy. From an environmental point of view, the mechanisms of Pb fixation should be improved in a granular state.
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safe use of electric arc furnace dust as Secondary Raw Material in self compacting mortars production
Journal of Cleaner Production, 2019Co-Authors: Angelica Lozanolunar, Pedro Raposeiro Da Silva, Jorge De Brito, J M Fernandez, Jose Ramon JimenezAbstract:Abstract This research contributes to the development of the Circular Economy concept by managing waste through its use as a construction Material. A novel process in which two samples of industrial waste Electric Arc Furnace Dust collected from two different steelwork plants are used as Secondary Raw Material in the production of self-compacting mortars is proposed. At a previous stage, a characterisation of mortar Material components was carried out. Then, self-compacting mortars with replacement ratios of 25%, 50% and 100% of siliceous filler with Electric Arc Furnace Dust were designed. The feasibility of Electric Arc Furnace Dust use was analysed by means of the study of mechanical strength, mineralogical, capillary properties and leaching behaviour in monolithic and granular state. The environmental classification of mortars, according to their leaching behaviour, was carried out in accordance with European Directive 2003/33/EC (2003). Electric Arc Furnace Dust incorporation modified the self-compactability and common hydration reactions. Mechanical strength decreased with Electric Arc Furnace Dust incorporation, although the mortar with 25% of replacement with one of the Electric Arc Furnace Dust's showed a negligible loss compared to the self-compacting reference mortar. Water absorption by capillarity increased with Electric Arc Furnace Dust content, consistently with the mortars' mechanical behaviour. The leaching behaviour analysis in a monolithic state revealed that all mortar releases were below the permitted limit. In a granular state, the mortar with the best mechanical behaviour was environmentally safe, leaving all the elements encapsulated by the self-compacting matrix. The results of this study contribute to Electric Arc Furnace Dust management through its valorisation as Secondary Raw Material in the production of self-compacting mortars, addressing an unprecedented line of research.
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Promotion of Circular Economy: Steelwork Dusts as Secondary Raw Material in Conventional Mortars
Proceedings, 2018Co-Authors: Angélica Lozano-lunar, Auxi Barbudo, Jose-maria Fernandez, Jose Ramon JimenezAbstract:Among the actions proposed by the European Union for the implementation of Circular Economy is the use of waste as a Secondary Raw Material (SRM). During the fusion of the scrap, a steel dust is generated, named Electric Arc Furnace Dust (EAFD). The EAFD is composed mainly of potentially leachable heavy metals, so is classified as “hazardous” waste. Around the world, approximately 70% of this waste is deposited in landfills, with a previous treatment through cement-based Materials to prevent the metals’ mobility. However, this action is not in accordance with the Circular Economy concept due to the greater use of resources and the loss of deposited metals. The present investigation analyses the use of EAFD as SRM in conventional mortar production for its use as a construction Material. Different substitution percentages (25%, 50% and 100%) were used replacing siliceous filler by EAFD. The investigation analysed the behaviour of conventional mortars by tests of workability, compressive strength, water absorption by capillarity and leaching behaviour in granular and monolithic state. The results obtained indicate a slight improvement in mechanical behaviour with the incorporation of EAFD, the reason why its use as SRM in conventional mortars would benefit the construction industry and would encourage the Circular Economy. From an environmental point of view, the mechanisms of Pb fixation should be improved in granular state.