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Takashi Fujimori - One of the best experts on this subject based on the ideXlab platform.
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the effect of gas emission on the strength of composite products derived using alkali activated municipal solid waste incineration fly ash Pyrophyllite based systems
Chemosphere, 2019Co-Authors: Kenji Shiota, Kazuyuki Oshita, Takashi Fujimori, Takahiro Toda, Hironori Kaji, Ayaka Maeno, Masaki TakaokaAbstract:Abstract We explored the effects of gas emission by mixtures undergoing alkali-activation of municipal solid waste incineration fly ash (MSWIFA) and Pyrophyllite (the mixtures included dehydrated Pyrophyllite, MSWIFA, 14 mol/L aqueous sodium hydroxide, and sodium silicate; curing proceed at 105 °C for 24 h). We measured the compressive strengths of the derived solid composites. The causes of gas emission, and the physical and chemical properties of products created under controlled gas emission, were investigated. Hydrogen was emitted after mixing MSWIFA and alkali. The compressive strength of products prepared when gas emission was complete was 2–3.4-fold greater than that of products prepared when gas emission was incomplete. X-ray micro-tomography and mercury intrusion porosimetry showed that products formed during complete gas emission tended to have smaller pores. X-ray diffraction and nuclear magnetic resonance (27Al and 29Si) indicated that the aluminum substitution levels in tectosilicate differed under such conditions, although the minerals were identical. Thus, complete gas emission after mixing improved ultimate products.
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stabilization of cesium in alkali activated municipal solid waste incineration fly ash and a Pyrophyllite based system
Chemosphere, 2017Co-Authors: Kenji Shiota, Takafumi Nakamura, Masaki Takaoka, Siti Fatimah Aminuddin, Kazuyuki Oshita, Takashi FujimoriAbstract:Abstract Environmentally sound treatments are required to dispose of municipal solid waste incineration fly ash (MSWIFA) contaminated with radioactive cesium (Cs) from the Fukushima Daiichi nuclear power plant accident in Japan. This study focuses on the stabilization of Cs using an alkali-activated MSWIFA and pyophyllite-based system. Three composite solid products were synthesized after mixtures of raw materials (dehydrated Pyrophyllite, MSWIFA, 14 mol/L aqueous sodium hydroxide, and sodium silicate solution) were cured at 105 °C for 24 h. Three types of MSWIFAs were prepared as raw fly ash, raw fly ash with 0.1% CsCl, and raw fly ash with 40% CsCl to understand the stabilization mechanism of Cs. Cs stabilization in two solid products was successful, with less than 6.9% leaching observed from two types tests, and was partly successful for the solid product with the highest concentration of Cs. X-ray diffraction showed that all of the solid products produced several crystalline phases, and that pollucite was formed in the highest Cs concentration product. The X-ray absorption fine structure and scanning electron microscopy with X-ray analysis suggested that most Cs species formed pollucite in the two solid products from MSWIFA with added CsCl. This system provides a technique for the direct stabilization of Cs in MSWIFA.
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stabilization of lead in an alkali activated municipal solid waste incineration fly ash Pyrophyllite based system
Journal of Environmental Management, 2017Co-Authors: Kenji Shiota, Takafumi Nakamura, Masaki Takaoka, Siti Fatimah Aminuddin, Kazuyuki Oshita, Takashi FujimoriAbstract:This work focuses on the stabilization and speciation of lead (Pb) in a composite solid produced from an alkali-activated municipal solid waste incineration fly ash (MSWIFA)–pyophyllite-based system. The solid product was synthesized after mixtures of raw materials (dehydrated Pyrophyllite, MSWIFA, 14 mol/L aqueous sodium hydroxide, and sodium silicate solution) were cured at 105 °C for 24 h. The product could reduce the leaching of Pb and the Pb concentration in the leachate was 7.0 × 10−3 using the Japanese leaching test and 9.7 × 10−4 mg/L using toxicity characteristics leaching procedure method, which satisfied the respective test criteria and successfully stabilized Pb in this system. The solid product had a compressive strength of 2 MPa and consisted mainly of crystalline phases. Scanning electron microscopy with X-ray analysis and X-ray absorption fine structure suggested that Pb was present along with Al, Si, and O, and that the atomic environment around the Pb was similar to that of PbSiO3. These results suggest that the alkali-activated MSWIFA–Pyrophyllite-based system could be used to stabilize Pb in MSWIFA.
Kenji Shiota - One of the best experts on this subject based on the ideXlab platform.
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the effect of gas emission on the strength of composite products derived using alkali activated municipal solid waste incineration fly ash Pyrophyllite based systems
Chemosphere, 2019Co-Authors: Kenji Shiota, Kazuyuki Oshita, Takashi Fujimori, Takahiro Toda, Hironori Kaji, Ayaka Maeno, Masaki TakaokaAbstract:Abstract We explored the effects of gas emission by mixtures undergoing alkali-activation of municipal solid waste incineration fly ash (MSWIFA) and Pyrophyllite (the mixtures included dehydrated Pyrophyllite, MSWIFA, 14 mol/L aqueous sodium hydroxide, and sodium silicate; curing proceed at 105 °C for 24 h). We measured the compressive strengths of the derived solid composites. The causes of gas emission, and the physical and chemical properties of products created under controlled gas emission, were investigated. Hydrogen was emitted after mixing MSWIFA and alkali. The compressive strength of products prepared when gas emission was complete was 2–3.4-fold greater than that of products prepared when gas emission was incomplete. X-ray micro-tomography and mercury intrusion porosimetry showed that products formed during complete gas emission tended to have smaller pores. X-ray diffraction and nuclear magnetic resonance (27Al and 29Si) indicated that the aluminum substitution levels in tectosilicate differed under such conditions, although the minerals were identical. Thus, complete gas emission after mixing improved ultimate products.
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stabilization of cesium in alkali activated municipal solid waste incineration fly ash and a Pyrophyllite based system
Chemosphere, 2017Co-Authors: Kenji Shiota, Takafumi Nakamura, Masaki Takaoka, Siti Fatimah Aminuddin, Kazuyuki Oshita, Takashi FujimoriAbstract:Abstract Environmentally sound treatments are required to dispose of municipal solid waste incineration fly ash (MSWIFA) contaminated with radioactive cesium (Cs) from the Fukushima Daiichi nuclear power plant accident in Japan. This study focuses on the stabilization of Cs using an alkali-activated MSWIFA and pyophyllite-based system. Three composite solid products were synthesized after mixtures of raw materials (dehydrated Pyrophyllite, MSWIFA, 14 mol/L aqueous sodium hydroxide, and sodium silicate solution) were cured at 105 °C for 24 h. Three types of MSWIFAs were prepared as raw fly ash, raw fly ash with 0.1% CsCl, and raw fly ash with 40% CsCl to understand the stabilization mechanism of Cs. Cs stabilization in two solid products was successful, with less than 6.9% leaching observed from two types tests, and was partly successful for the solid product with the highest concentration of Cs. X-ray diffraction showed that all of the solid products produced several crystalline phases, and that pollucite was formed in the highest Cs concentration product. The X-ray absorption fine structure and scanning electron microscopy with X-ray analysis suggested that most Cs species formed pollucite in the two solid products from MSWIFA with added CsCl. This system provides a technique for the direct stabilization of Cs in MSWIFA.
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stabilization of lead in an alkali activated municipal solid waste incineration fly ash Pyrophyllite based system
Journal of Environmental Management, 2017Co-Authors: Kenji Shiota, Takafumi Nakamura, Masaki Takaoka, Siti Fatimah Aminuddin, Kazuyuki Oshita, Takashi FujimoriAbstract:This work focuses on the stabilization and speciation of lead (Pb) in a composite solid produced from an alkali-activated municipal solid waste incineration fly ash (MSWIFA)–pyophyllite-based system. The solid product was synthesized after mixtures of raw materials (dehydrated Pyrophyllite, MSWIFA, 14 mol/L aqueous sodium hydroxide, and sodium silicate solution) were cured at 105 °C for 24 h. The product could reduce the leaching of Pb and the Pb concentration in the leachate was 7.0 × 10−3 using the Japanese leaching test and 9.7 × 10−4 mg/L using toxicity characteristics leaching procedure method, which satisfied the respective test criteria and successfully stabilized Pb in this system. The solid product had a compressive strength of 2 MPa and consisted mainly of crystalline phases. Scanning electron microscopy with X-ray analysis and X-ray absorption fine structure suggested that Pb was present along with Al, Si, and O, and that the atomic environment around the Pb was similar to that of PbSiO3. These results suggest that the alkali-activated MSWIFA–Pyrophyllite-based system could be used to stabilize Pb in MSWIFA.
Masaki Takaoka - One of the best experts on this subject based on the ideXlab platform.
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the effect of gas emission on the strength of composite products derived using alkali activated municipal solid waste incineration fly ash Pyrophyllite based systems
Chemosphere, 2019Co-Authors: Kenji Shiota, Kazuyuki Oshita, Takashi Fujimori, Takahiro Toda, Hironori Kaji, Ayaka Maeno, Masaki TakaokaAbstract:Abstract We explored the effects of gas emission by mixtures undergoing alkali-activation of municipal solid waste incineration fly ash (MSWIFA) and Pyrophyllite (the mixtures included dehydrated Pyrophyllite, MSWIFA, 14 mol/L aqueous sodium hydroxide, and sodium silicate; curing proceed at 105 °C for 24 h). We measured the compressive strengths of the derived solid composites. The causes of gas emission, and the physical and chemical properties of products created under controlled gas emission, were investigated. Hydrogen was emitted after mixing MSWIFA and alkali. The compressive strength of products prepared when gas emission was complete was 2–3.4-fold greater than that of products prepared when gas emission was incomplete. X-ray micro-tomography and mercury intrusion porosimetry showed that products formed during complete gas emission tended to have smaller pores. X-ray diffraction and nuclear magnetic resonance (27Al and 29Si) indicated that the aluminum substitution levels in tectosilicate differed under such conditions, although the minerals were identical. Thus, complete gas emission after mixing improved ultimate products.
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stabilization of cesium in alkali activated municipal solid waste incineration fly ash and a Pyrophyllite based system
Chemosphere, 2017Co-Authors: Kenji Shiota, Takafumi Nakamura, Masaki Takaoka, Siti Fatimah Aminuddin, Kazuyuki Oshita, Takashi FujimoriAbstract:Abstract Environmentally sound treatments are required to dispose of municipal solid waste incineration fly ash (MSWIFA) contaminated with radioactive cesium (Cs) from the Fukushima Daiichi nuclear power plant accident in Japan. This study focuses on the stabilization of Cs using an alkali-activated MSWIFA and pyophyllite-based system. Three composite solid products were synthesized after mixtures of raw materials (dehydrated Pyrophyllite, MSWIFA, 14 mol/L aqueous sodium hydroxide, and sodium silicate solution) were cured at 105 °C for 24 h. Three types of MSWIFAs were prepared as raw fly ash, raw fly ash with 0.1% CsCl, and raw fly ash with 40% CsCl to understand the stabilization mechanism of Cs. Cs stabilization in two solid products was successful, with less than 6.9% leaching observed from two types tests, and was partly successful for the solid product with the highest concentration of Cs. X-ray diffraction showed that all of the solid products produced several crystalline phases, and that pollucite was formed in the highest Cs concentration product. The X-ray absorption fine structure and scanning electron microscopy with X-ray analysis suggested that most Cs species formed pollucite in the two solid products from MSWIFA with added CsCl. This system provides a technique for the direct stabilization of Cs in MSWIFA.
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stabilization of lead in an alkali activated municipal solid waste incineration fly ash Pyrophyllite based system
Journal of Environmental Management, 2017Co-Authors: Kenji Shiota, Takafumi Nakamura, Masaki Takaoka, Siti Fatimah Aminuddin, Kazuyuki Oshita, Takashi FujimoriAbstract:This work focuses on the stabilization and speciation of lead (Pb) in a composite solid produced from an alkali-activated municipal solid waste incineration fly ash (MSWIFA)–pyophyllite-based system. The solid product was synthesized after mixtures of raw materials (dehydrated Pyrophyllite, MSWIFA, 14 mol/L aqueous sodium hydroxide, and sodium silicate solution) were cured at 105 °C for 24 h. The product could reduce the leaching of Pb and the Pb concentration in the leachate was 7.0 × 10−3 using the Japanese leaching test and 9.7 × 10−4 mg/L using toxicity characteristics leaching procedure method, which satisfied the respective test criteria and successfully stabilized Pb in this system. The solid product had a compressive strength of 2 MPa and consisted mainly of crystalline phases. Scanning electron microscopy with X-ray analysis and X-ray absorption fine structure suggested that Pb was present along with Al, Si, and O, and that the atomic environment around the Pb was similar to that of PbSiO3. These results suggest that the alkali-activated MSWIFA–Pyrophyllite-based system could be used to stabilize Pb in MSWIFA.
Navin Chandra - One of the best experts on this subject based on the ideXlab platform.
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coal fly ash utilization low temperature sintering of wall tiles
Waste Management, 2008Co-Authors: Navin Chandra, G. L. Pashkov, S. S. Amritphale, Priya Sharma, E.n. Voskresenskaya, Narendra S. BaghelAbstract:Abstract We present here a study of the sintering of fly ash and its mixture with low alkali Pyrophyllite in the presence of sodium hexa meta phosphate (SHMP), a complex activator of sintering, for the purpose of wall tile manufacturing. The sintering of fly ash with SHMP in the temperature range 925–1050 °C produces tiles with low impact strength; however, the incremental addition of low alkali Pyrophyllite improves impact strength. The impact strength of composites with ⩾40% (w/w) Pyrophyllite in the fly ash–Pyrophyllite mix satisfies the acceptable limit (19.6 J/m) set by the Indian Standards Institute for wall tiles. Increasing the Pyrophyllite content results in an increase in the apparent density of tiles, while shrinkage and water absorption decrease. The strength of fly ash tiles is attributed to the formation of a silicophosphate phase; in Pyrophyllite rich tiles, it is attributed to the formation of a tridymite-structured T-AlPO 4 phase. Scanning electron micrographs show that the reinforcing rod shaped T-AlPO 4 crystals become more prominent as the Pyrophyllite content increases in the sintered tiles.
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coal fly ash utilization low temperature sintering of wall tiles
Waste Management, 2008Co-Authors: Navin Chandra, G. L. Pashkov, S. S. Amritphale, Priya Sharma, E.n. Voskresenskaya, Narendra S. BaghelAbstract:We present here a study of the sintering of fly ash and its mixture with low alkali Pyrophyllite in the presence of sodium hexa meta phosphate (SHMP), a complex activator of sintering, for the purpose of wall tile manufacturing. The sintering of fly ash with SHMP in the temperature range 925-1050 degrees C produces tiles with low impact strength; however, the incremental addition of low alkali Pyrophyllite improves impact strength. The impact strength of composites with >or=40% (w/w) Pyrophyllite in the fly ash-Pyrophyllite mix satisfies the acceptable limit (19.6 J/m) set by the Indian Standards Institute for wall tiles. Increasing the Pyrophyllite content results in an increase in the apparent density of tiles, while shrinkage and water absorption decrease. The strength of fly ash tiles is attributed to the formation of a silicophosphate phase; in Pyrophyllite rich tiles, it is attributed to the formation of a tridymite-structured T-AlPO(4) phase. Scanning electron micrographs show that the reinforcing rod shaped T-AlPO(4) crystals become more prominent as the Pyrophyllite content increases in the sintered tiles.
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energy efficient process for making Pyrophyllite based ceramic tiles using phosphoric acid and mineralizers
Ceramics International, 2006Co-Authors: S. S. Amritphale, Sanjeev Bhasin, Navin ChandraAbstract:Abstract The processing parameters for making ceramic tiles in the Pyrophyllite–phosphoric acid binder (P–PA) system have been optimized. The optimized raw material composition requires sintering at a lower temperature of 950 °C. The X-ray powder diffraction studies on the powdered sample of optimized composition have confirmed the presence of dehydroxylate Pyrophyllite, tridymite (T-AlPO4), cristyoballite (C-AlPO4) forms of aluminium phosphate and formation of silico-phosphate (SiP2O7) and alkali aluminium silicates (NaAlSiO4, KAlSi3O8). The IR studies of the sample show Al–O, Si–O·P–O and Na/K–O linkages. The thermal analysis shows the formation of dehydroxylate Pyrophyllite and different forms of AlPO4. Scanning electron microphotograph reveals the chunky morphology of the dehydroxylate Pyrophyllite, the rhombohedral morphology of T-AlPO4 and spherical C-AlPO4 and silico-phosphate particles.
Kazuyuki Oshita - One of the best experts on this subject based on the ideXlab platform.
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the effect of gas emission on the strength of composite products derived using alkali activated municipal solid waste incineration fly ash Pyrophyllite based systems
Chemosphere, 2019Co-Authors: Kenji Shiota, Kazuyuki Oshita, Takashi Fujimori, Takahiro Toda, Hironori Kaji, Ayaka Maeno, Masaki TakaokaAbstract:Abstract We explored the effects of gas emission by mixtures undergoing alkali-activation of municipal solid waste incineration fly ash (MSWIFA) and Pyrophyllite (the mixtures included dehydrated Pyrophyllite, MSWIFA, 14 mol/L aqueous sodium hydroxide, and sodium silicate; curing proceed at 105 °C for 24 h). We measured the compressive strengths of the derived solid composites. The causes of gas emission, and the physical and chemical properties of products created under controlled gas emission, were investigated. Hydrogen was emitted after mixing MSWIFA and alkali. The compressive strength of products prepared when gas emission was complete was 2–3.4-fold greater than that of products prepared when gas emission was incomplete. X-ray micro-tomography and mercury intrusion porosimetry showed that products formed during complete gas emission tended to have smaller pores. X-ray diffraction and nuclear magnetic resonance (27Al and 29Si) indicated that the aluminum substitution levels in tectosilicate differed under such conditions, although the minerals were identical. Thus, complete gas emission after mixing improved ultimate products.
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stabilization of cesium in alkali activated municipal solid waste incineration fly ash and a Pyrophyllite based system
Chemosphere, 2017Co-Authors: Kenji Shiota, Takafumi Nakamura, Masaki Takaoka, Siti Fatimah Aminuddin, Kazuyuki Oshita, Takashi FujimoriAbstract:Abstract Environmentally sound treatments are required to dispose of municipal solid waste incineration fly ash (MSWIFA) contaminated with radioactive cesium (Cs) from the Fukushima Daiichi nuclear power plant accident in Japan. This study focuses on the stabilization of Cs using an alkali-activated MSWIFA and pyophyllite-based system. Three composite solid products were synthesized after mixtures of raw materials (dehydrated Pyrophyllite, MSWIFA, 14 mol/L aqueous sodium hydroxide, and sodium silicate solution) were cured at 105 °C for 24 h. Three types of MSWIFAs were prepared as raw fly ash, raw fly ash with 0.1% CsCl, and raw fly ash with 40% CsCl to understand the stabilization mechanism of Cs. Cs stabilization in two solid products was successful, with less than 6.9% leaching observed from two types tests, and was partly successful for the solid product with the highest concentration of Cs. X-ray diffraction showed that all of the solid products produced several crystalline phases, and that pollucite was formed in the highest Cs concentration product. The X-ray absorption fine structure and scanning electron microscopy with X-ray analysis suggested that most Cs species formed pollucite in the two solid products from MSWIFA with added CsCl. This system provides a technique for the direct stabilization of Cs in MSWIFA.
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stabilization of lead in an alkali activated municipal solid waste incineration fly ash Pyrophyllite based system
Journal of Environmental Management, 2017Co-Authors: Kenji Shiota, Takafumi Nakamura, Masaki Takaoka, Siti Fatimah Aminuddin, Kazuyuki Oshita, Takashi FujimoriAbstract:This work focuses on the stabilization and speciation of lead (Pb) in a composite solid produced from an alkali-activated municipal solid waste incineration fly ash (MSWIFA)–pyophyllite-based system. The solid product was synthesized after mixtures of raw materials (dehydrated Pyrophyllite, MSWIFA, 14 mol/L aqueous sodium hydroxide, and sodium silicate solution) were cured at 105 °C for 24 h. The product could reduce the leaching of Pb and the Pb concentration in the leachate was 7.0 × 10−3 using the Japanese leaching test and 9.7 × 10−4 mg/L using toxicity characteristics leaching procedure method, which satisfied the respective test criteria and successfully stabilized Pb in this system. The solid product had a compressive strength of 2 MPa and consisted mainly of crystalline phases. Scanning electron microscopy with X-ray analysis and X-ray absorption fine structure suggested that Pb was present along with Al, Si, and O, and that the atomic environment around the Pb was similar to that of PbSiO3. These results suggest that the alkali-activated MSWIFA–Pyrophyllite-based system could be used to stabilize Pb in MSWIFA.
