Y. Kanemitsu, Li Pang Wang, Gjergj Dodbiba, T. Fujita
A liquid-liquid separation method using aqueous and oil phases has been put forward for separation of fine zircon-alumina mixtures to recycle abrasives waste. By using a cation surfactant, zircon particles were made hydrophobic and extracted into the oil phase, whereas alumina remained in the aqueous phase. In this way, the fine zircon-alumina mixtures could be well separated. The result confirmed that the liquid-liquid separation method can be used to separate the fine zirconalumina mixtures achieving relatively high grade and recovery.
{"title":"Liquid-Liquid Separation of Fine Zircon-Alumina Mixtures for Abrasives Recycling","authors":"Y. Kanemitsu, Li Pang Wang, Gjergj Dodbiba, T. Fujita","doi":"10.4144/RPSJ.59.81","DOIUrl":"https://doi.org/10.4144/RPSJ.59.81","url":null,"abstract":"A liquid-liquid separation method using aqueous and oil phases has been put forward for separation of fine zircon-alumina mixtures to recycle abrasives waste. By using a cation surfactant, zircon particles were made hydrophobic and extracted into the oil phase, whereas alumina remained in the aqueous phase. In this way, the fine zircon-alumina mixtures could be well separated. The result confirmed that the liquid-liquid separation method can be used to separate the fine zirconalumina mixtures achieving relatively high grade and recovery.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73049116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Moringa oleifera (M. oleifera) is one of the most widely spread Moringa species that grows quickly in the tropical belt. The objective of this study was to investigate the influence of the aqueous pH, initial turbidity of the synthetic kaolin turbid water, ionic strength, and humic substances on the efficiency of the M. oleifera coagulant. The experimental results showed that the coagulation efficiency was significantly enhanced by the presence of divalent cations such as Ca or Mg, and slightly enhanced by lowering the aqueous pH from 9.0 to 4.0. It was also found that fulvic acid did not significantly affect the coagulation efficiency, while the initial turbidity and humic acid did. M. oleifera coagulant was effective for synthetic waters of an initial turbidity of 290 NTU. However, turbidity removal was not observed when the initial turbidity was lowered to 45 NTU. The presence of humic acid significantly increased the coagulant dosage required for turbidity removal. These obtained experimental observations were then used to discuss the influence of the water quality on the dominant coagulation mechanism.
{"title":"Influence of Water Quality on Turbidity Removal by Coagulation with Moringa Oleifera Seeds","authors":"Tasuma Suzuki, Masakazu Niinae, Yasuaki Sanada","doi":"10.4144/RPSJ.59.73","DOIUrl":"https://doi.org/10.4144/RPSJ.59.73","url":null,"abstract":"Moringa oleifera (M. oleifera) is one of the most widely spread Moringa species that grows quickly in the tropical belt. The objective of this study was to investigate the influence of the aqueous pH, initial turbidity of the synthetic kaolin turbid water, ionic strength, and humic substances on the efficiency of the M. oleifera coagulant. The experimental results showed that the coagulation efficiency was significantly enhanced by the presence of divalent cations such as Ca or Mg, and slightly enhanced by lowering the aqueous pH from 9.0 to 4.0. It was also found that fulvic acid did not significantly affect the coagulation efficiency, while the initial turbidity and humic acid did. M. oleifera coagulant was effective for synthetic waters of an initial turbidity of 290 NTU. However, turbidity removal was not observed when the initial turbidity was lowered to 45 NTU. The presence of humic acid significantly increased the coagulant dosage required for turbidity removal. These obtained experimental observations were then used to discuss the influence of the water quality on the dominant coagulation mechanism.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74413600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Titanium and its alloys have been used in bone plates/screws; these are designed to be removed after recovery. However, bone can sometimes bond to surface of implanted materials that remain in the body for long periods of time. This can lead to re-fracture of newly repaired bone during operations to remove the implants. The purpose of the present study was to synthesize bioinert films, including ZrO2 on pure Ti surfaces and to investigate hydroxyapatite (HAp) formation on the synthesized films in simulated body fluid (SBF). Pure Ti disks were chemically treated with H2O2/ HNO3 aqueous solutions at 353 K for 20 min. The disks were hydrothermally treated with ZrOCl2/ NH3/C6H8O7 (citric acid) aqueous solutions at 453 K for 12 h. The specimens were immersed in SBF, which was maintained at 310 K. After being soaked for different periods of time, the surfaces were observed by SEM. In the hydrothermal treatment with ZrOCl2/NH3 aqueous solution, the surface product was anatase-type TiO2. On the other hand, when citric acid was added the surface of Ti was covered homogeneously with a TiO2-ZrO2 composite film. This surface suppressed the precipitation of HAp during SBF soaking.
{"title":"Hydrothermal Synthesis of Bioinert TiO2-ZrO2 Films on Ti Substrates with Zr-dissolved Alkaline Solutions","authors":"Ryuichi Kozakura, M. Ueda, M. Ikeda","doi":"10.4144/RPSJ.59.17","DOIUrl":"https://doi.org/10.4144/RPSJ.59.17","url":null,"abstract":"Titanium and its alloys have been used in bone plates/screws; these are designed to be removed after recovery. However, bone can sometimes bond to surface of implanted materials that remain in the body for long periods of time. This can lead to re-fracture of newly repaired bone during operations to remove the implants. The purpose of the present study was to synthesize bioinert films, including ZrO2 on pure Ti surfaces and to investigate hydroxyapatite (HAp) formation on the synthesized films in simulated body fluid (SBF). Pure Ti disks were chemically treated with H2O2/ HNO3 aqueous solutions at 353 K for 20 min. The disks were hydrothermally treated with ZrOCl2/ NH3/C6H8O7 (citric acid) aqueous solutions at 453 K for 12 h. The specimens were immersed in SBF, which was maintained at 310 K. After being soaked for different periods of time, the surfaces were observed by SEM. In the hydrothermal treatment with ZrOCl2/NH3 aqueous solution, the surface product was anatase-type TiO2. On the other hand, when citric acid was added the surface of Ti was covered homogeneously with a TiO2-ZrO2 composite film. This surface suppressed the precipitation of HAp during SBF soaking.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86154236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper demonstrates the importance of comminution for achieving compositional liberation in order to establish an effective solid-solid separation process, in especial, in the field of mineral processing and resources recycling. We have developed a unique liberation model in comminution process by introducing an index of “preferential breakage probability”, e 1 , at phase boundary to the Wiegel model, which is well known in the field of mineral processing. From the results, we easily understood that the degree of liberation gradually increased with increasing the e 1 and it could be demonstrated that the energy required for obtaining a certain degree of liberation dramatically decreased with increasing the e 1 . This calculation indicated the importance of preferential breakage at phase boundary in comminution with lower energy consumption, which could contribute better separation efficiency in the following solid-solid separation. In other words, the e 1 must become a good index for the DfR (Design for Recycling) as an “EcoDesign” from the viewpoint of compositional separation. The paper also describes several recent approaches to obtain a good liberation of structural components in comminution, such as (semi)-autogenous grinding, surface grinding, blasting in water, microwave pretreatment, and electrical disintegration.
{"title":"Role of Comminution as a Pretreatment of Physical Concentration in Resources Recycling","authors":"S. Owada","doi":"10.4144/RPSJ.59.3","DOIUrl":"https://doi.org/10.4144/RPSJ.59.3","url":null,"abstract":"This paper demonstrates the importance of comminution for achieving compositional liberation in order to establish an effective solid-solid separation process, in especial, in the field of mineral processing and resources recycling. We have developed a unique liberation model in comminution process by introducing an index of “preferential breakage probability”, e 1 , at phase boundary to the Wiegel model, which is well known in the field of mineral processing. From the results, we easily understood that the degree of liberation gradually increased with increasing the e 1 and it could be demonstrated that the energy required for obtaining a certain degree of liberation dramatically decreased with increasing the e 1 . This calculation indicated the importance of preferential breakage at phase boundary in comminution with lower energy consumption, which could contribute better separation efficiency in the following solid-solid separation. In other words, the e 1 must become a good index for the DfR (Design for Recycling) as an “EcoDesign” from the viewpoint of compositional separation. The paper also describes several recent approaches to obtain a good liberation of structural components in comminution, such as (semi)-autogenous grinding, surface grinding, blasting in water, microwave pretreatment, and electrical disintegration.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82370980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An essential requirement for adequate BaTiO3 suspension is low viscosity at high shear rates for the ease of shaping and a suitable yield stress to maintain the shape after the forming process. The appropriate range of viscosity is reported to be 800–1100 mPa·s at a shear rate of 100 s. Particles need to be in a well-dispersed state to achieve homogenous and fine grain structure in a final sintered product. Four different kinds of phosphate ester were examined about the role as dispersant for submicrosized BaTiO3 particles suspended in toluene-ethanol media. In order to find out the effect of phosphate ester on dispersion state of the suspensions, rheological properties, median size and zeta potential of obtained suspensions were investigated. Oleyl acid phosphate gave the best result as the median diameter of BT-01 is reduced to 0.34 μm in toluene-ethanol media by adding 1mass% oleyl acid phosphate. It is suggested that dispersion enhanced by oleyl acid phosphate is based on steric hindrance due to the large alkyl chain.
{"title":"Dispersion of Nano-sized BaTiO3 Particles in Toluene-Ethanol Media Using Phosphate Ester","authors":"J. Shibata, N. Murayama, Hyoung-Ho Lee","doi":"10.4144/RPSJ.59.125","DOIUrl":"https://doi.org/10.4144/RPSJ.59.125","url":null,"abstract":"An essential requirement for adequate BaTiO3 suspension is low viscosity at high shear rates for the ease of shaping and a suitable yield stress to maintain the shape after the forming process. The appropriate range of viscosity is reported to be 800–1100 mPa·s at a shear rate of 100 s. Particles need to be in a well-dispersed state to achieve homogenous and fine grain structure in a final sintered product. Four different kinds of phosphate ester were examined about the role as dispersant for submicrosized BaTiO3 particles suspended in toluene-ethanol media. In order to find out the effect of phosphate ester on dispersion state of the suspensions, rheological properties, median size and zeta potential of obtained suspensions were investigated. Oleyl acid phosphate gave the best result as the median diameter of BT-01 is reduced to 0.34 μm in toluene-ethanol media by adding 1mass% oleyl acid phosphate. It is suggested that dispersion enhanced by oleyl acid phosphate is based on steric hindrance due to the large alkyl chain.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85709241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Waste cement powder, which is generated after separation and recovery of aggregates from concrete waste, was attempted to reuse as a raw material of geopolymer hardened material. The geopolymer attracts attention as a new material to replace conventional cement, because the geopolymer emits less carbon dioxide compared with the conventional cement during its manufacturing process and has high resistance to acids and heat. In this study, the geopolymer hardened material was prepared from mixed powder of waste cement and granulated blast furnace slag. The prepared geopolymer hardened material had a high compressive strength over 24 N/mm enough to be used as construction material. When the mixing ratio of the waste cement powder and the granulated blast furnace slag was 40 : 60, the compressive strength was 76.8 N/mm.
{"title":"Preparation of High Strength Geopolymer Hardened Material from Waste Concrete","authors":"T. Hongo, Kanae Igarashi, A. Iizuka, A. Yamasaki","doi":"10.4144/RPSJ.59.137","DOIUrl":"https://doi.org/10.4144/RPSJ.59.137","url":null,"abstract":"Waste cement powder, which is generated after separation and recovery of aggregates from concrete waste, was attempted to reuse as a raw material of geopolymer hardened material. The geopolymer attracts attention as a new material to replace conventional cement, because the geopolymer emits less carbon dioxide compared with the conventional cement during its manufacturing process and has high resistance to acids and heat. In this study, the geopolymer hardened material was prepared from mixed powder of waste cement and granulated blast furnace slag. The prepared geopolymer hardened material had a high compressive strength over 24 N/mm enough to be used as construction material. When the mixing ratio of the waste cement powder and the granulated blast furnace slag was 40 : 60, the compressive strength was 76.8 N/mm.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76344859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Masakazu Niinae, Tasuma Suzuki, Tomonori Nakamura, Y. Inoue, J. Shibata
The lithium ion secondary batteries (LIBs) contain valuable metallic components and although spent LIBs are not generally classified as dangerous waste, recovery of these metals is necessary from an economic point of view. In this work, separation of main metals such as aluminum, copper, cobalt and lithium contained in spent LIBs has been inves-tigated using a hydrometallurgical treatment based on solvent extraction. The results obtained this study are summa- rized as follows: Aluminum could not be selectively separated from copper and cobalt by the precipitation method as hydroxide because the precipitation curves of aluminum and copper were close and cobalt was precipitated due to the coprecip- itation with aluminum hydroxide or copper hydroxide. Meanwhile, aluminum could be selectively separated from cobalt and lithium with solvent extraction using PC-88A at pH 2.0–2.5 after the selective extraction of copper with Acorga M5640 at pH 1.0–2.0 while leaving cobalt and lithium in the raffinate. Acorga M5640 was efficient and selec- tive for the extraction of cobalt at pH of approximately 6.0 while leaving lithium in the raffinate. However, the stripping efficiency of Co from organic phase (Acorga M5640) was very low. Therefore, the extractant combination, PC-88A/TOA, was favorable to the separation of Co and Li at pH of approximately 5.0 compared with Acorga M5640. A separation process of aluminum, copper, cobalt and lithium from the spent LIBs using hydrometallurgical treatment based on solvent extraction was proposed.
{"title":"Separation Process of Metals from Hydrochloric Acid Leach Liquor of Spent Lithium Ion Batteries by Solvent Extraction","authors":"Masakazu Niinae, Tasuma Suzuki, Tomonori Nakamura, Y. Inoue, J. Shibata","doi":"10.4144/RPSJ.59.131","DOIUrl":"https://doi.org/10.4144/RPSJ.59.131","url":null,"abstract":"The lithium ion secondary batteries (LIBs) contain valuable metallic components and although spent LIBs are not generally classified as dangerous waste, recovery of these metals is necessary from an economic point of view. In this work, separation of main metals such as aluminum, copper, cobalt and lithium contained in spent LIBs has been inves-tigated using a hydrometallurgical treatment based on solvent extraction. The results obtained this study are summa- rized as follows: Aluminum could not be selectively separated from copper and cobalt by the precipitation method as hydroxide because the precipitation curves of aluminum and copper were close and cobalt was precipitated due to the coprecip- itation with aluminum hydroxide or copper hydroxide. Meanwhile, aluminum could be selectively separated from cobalt and lithium with solvent extraction using PC-88A at pH 2.0–2.5 after the selective extraction of copper with Acorga M5640 at pH 1.0–2.0 while leaving cobalt and lithium in the raffinate. Acorga M5640 was efficient and selec- tive for the extraction of cobalt at pH of approximately 6.0 while leaving lithium in the raffinate. However, the stripping efficiency of Co from organic phase (Acorga M5640) was very low. Therefore, the extractant combination, PC-88A/TOA, was favorable to the separation of Co and Li at pH of approximately 5.0 compared with Acorga M5640. A separation process of aluminum, copper, cobalt and lithium from the spent LIBs using hydrometallurgical treatment based on solvent extraction was proposed.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76328942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the present study, generation of iodine by an electrolytic oxidation from solutions containing iodide ions was investigated in order to develop a recycling process of gold using iodine-iodide solutions. In an anodic polarization curve, the current began to rise at an anodic potential of around 0.5 V vs. SHE, and solution near anode surface became brown, which is comparable to the thermodynamic potential for I 3 − /I − of 0.536 V vs. SHE. In the initial stage of galvanostatic electrolysis, iodine concentration increased with time and iodide concentration decreased. The current efficiencies were more than 90% in this stage. In the further electrolysis, iodine concentration decreased with time and solid state iodine was formed on the anode. The highest concentration of iodine could be estimated by the relationship between its solubility and the initial concentrations of iodine and iodide.
本研究研究了含碘离子溶液电解氧化生成碘的方法，以开发利用碘化碘溶液回收金的工艺。在阳极极化曲线中，电流在0.5 V / SHE左右的阳极电位处开始上升，阳极表面附近的溶液变成棕色，这与i3−/I−的热力学势0.536 V / SHE相当。在恒流电解初期，碘浓度随时间增加，碘化物浓度降低。在这一阶段，目前的效率超过90%。在进一步电解过程中，碘浓度随时间降低，在阳极上形成固态碘。根据碘的溶解度与碘和碘化物的初始浓度之间的关系，可以估计出碘的最高浓度。
{"title":"Generation of Iodine by Galvanostatic Electrolysis","authors":"K. Koyama, Mikiya Tanaka, J. Shibata","doi":"10.4144/RPSJ.58.136","DOIUrl":"https://doi.org/10.4144/RPSJ.58.136","url":null,"abstract":"In the present study, generation of iodine by an electrolytic oxidation from solutions containing iodide ions was investigated in order to develop a recycling process of gold using iodine-iodide solutions. In an anodic polarization curve, the current began to rise at an anodic potential of around 0.5 V vs. SHE, and solution near anode surface became brown, which is comparable to the thermodynamic potential for I 3 − /I − of 0.536 V vs. SHE. In the initial stage of galvanostatic electrolysis, iodine concentration increased with time and iodide concentration decreased. The current efficiencies were more than 90% in this stage. In the further electrolysis, iodine concentration decreased with time and solid state iodine was formed on the anode. The highest concentration of iodine could be estimated by the relationship between its solubility and the initial concentrations of iodine and iodide.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80271531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An arsenic removal unit was constructed by the Miyazaki University research group in Bangladesh. The sludge drained from the arsenic removal unit was directed to a sludge tank and allowed to settle down. Then the supernatant in the tank was released to an artificial pond. Biomethylation of arsenic is usually considered as a detoxification of arsenic because toxicity of most organic methylated arsenic is much less than that inorganic arsenic. Microorganisms in the sludge tank were evaluated growth characteristics and arsenic methylation. As a result, dimethylarsinic acid was detected in the broth, and the amount of total arsenic compounds in the broth decreased. It is thought that this loss was contributed by biogenic activity induced by inorganic arsenic biomethylation to gasified volatile organic species, such as monomethylarsine and dimethylarsine. These results suggested that microorganisms in the sludge tank may be utilized for natural attenuation of arsenic sludge from the arsenic removal unit.
{"title":"A Study on Arsenic Methylation by Microorganisms in Sludge Tank of Arsenic Removal Unit","authors":"M. Miyatake, S. Hayashi","doi":"10.4144/RPSJ.58.141","DOIUrl":"https://doi.org/10.4144/RPSJ.58.141","url":null,"abstract":"An arsenic removal unit was constructed by the Miyazaki University research group in Bangladesh. The sludge drained from the arsenic removal unit was directed to a sludge tank and allowed to settle down. Then the supernatant in the tank was released to an artificial pond. Biomethylation of arsenic is usually considered as a detoxification of arsenic because toxicity of most organic methylated arsenic is much less than that inorganic arsenic. Microorganisms in the sludge tank were evaluated growth characteristics and arsenic methylation. As a result, dimethylarsinic acid was detected in the broth, and the amount of total arsenic compounds in the broth decreased. It is thought that this loss was contributed by biogenic activity induced by inorganic arsenic biomethylation to gasified volatile organic species, such as monomethylarsine and dimethylarsine. These results suggested that microorganisms in the sludge tank may be utilized for natural attenuation of arsenic sludge from the arsenic removal unit.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81109809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fei Wang, Y. Yoshimura, S. Hirai, Toshihiro Kuzuya
The sol-gel synthesized powder was a single phase Li2ZrO3. This synthesized powder reacted with CO2 at temperatures from the ambient temperature to a high temperature. The reaction products reacted reversibly to form Li2ZrO3 at temperatures above 925 K. The degree of absorption was defined as the value obtained by dividing the fractional mass gain of Li2ZrO3 after absorption by the fractional mass gain corresponding to a 100% reaction. Consequently, the degree of absorption was determined to be 95.2% under the absorption condition of 773 K and 7.2 ks. When CO2 absorption at 773 K and release at 993 K were repeated five times to examine the cyclic behavior, the degree of absorption was almost the same as the initial amount. The degree of absorption of commercial powder prepared by a solid-solid reaction of Li2CO3 and ZrO2 was 10.6% under the same absorption condition. The degrees of absorption with the sol-gel synthesized powder were determined to be 26, 31 and 43% under the absorption conditions of 293, 313 and 333 K for an exposure time of 115.2 ks. The absorption behavior could be best explained by an intraparticle diffusion mechanism. The diffusion of CO2 gas through the reaction product with an apparent activation energy of 24 kJ·mol−1 was a rate-determining step of the absorption reaction.
{"title":"CO2 Absorption/Release Properties of Lithium Zirconate Powder Prepared by the Sol-Gel Process","authors":"Fei Wang, Y. Yoshimura, S. Hirai, Toshihiro Kuzuya","doi":"10.4144/RPSJ.58.108","DOIUrl":"https://doi.org/10.4144/RPSJ.58.108","url":null,"abstract":"The sol-gel synthesized powder was a single phase Li2ZrO3. This synthesized powder reacted with CO2 at temperatures from the ambient temperature to a high temperature. The reaction products reacted reversibly to form Li2ZrO3 at temperatures above 925 K. The degree of absorption was defined as the value obtained by dividing the fractional mass gain of Li2ZrO3 after absorption by the fractional mass gain corresponding to a 100% reaction. Consequently, the degree of absorption was determined to be 95.2% under the absorption condition of 773 K and 7.2 ks. When CO2 absorption at 773 K and release at 993 K were repeated five times to examine the cyclic behavior, the degree of absorption was almost the same as the initial amount. The degree of absorption of commercial powder prepared by a solid-solid reaction of Li2CO3 and ZrO2 was 10.6% under the same absorption condition. The degrees of absorption with the sol-gel synthesized powder were determined to be 26, 31 and 43% under the absorption conditions of 293, 313 and 333 K for an exposure time of 115.2 ks. The absorption behavior could be best explained by an intraparticle diffusion mechanism. The diffusion of CO2 gas through the reaction product with an apparent activation energy of 24 kJ·mol−1 was a rate-determining step of the absorption reaction.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80684965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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