Several metallic materials have been developed for many purposes by alloying and controlling microstructure. From the viewpoint of materials recycling, several properties should be controlled by the latter in simple alloys. Then, observation and evaluation of lattice defects such as vacancy, dislocation and grain boundary are very important for understanding microstructure development during thermo-mechanical treatments. The purpose of this study was to establish a method for esti-mating density of lattice defects in cold rolled and annealed Ti by a precise measurement of electrical resistivity. Pure Ti plates were cold rolled at room temperature. Bar shaped specimens were cut from the plates. Electrical resistivities at 77 K (liquid nitrogen) and 300 K were measured by a direct current four-point method with a constant current of 100 mA. The accuracy of temperature control at 300 K was 0.1 K in silicone oil. Basically the electrical resistivities gradually increased with increasing a reduction of thickness. The density of dislocation was determined to be 2–8 × 10 14 m − 2 in the 15–80% CR specimens
{"title":"Evaluation of Lattice Defect Density in Deformed Ti by Precise Measurement of Electrical Resistivity","authors":"M. Ueda, Keiichi Ota, M. Ikeda","doi":"10.4144/RPSJ.60.18","DOIUrl":"https://doi.org/10.4144/RPSJ.60.18","url":null,"abstract":"Several metallic materials have been developed for many purposes by alloying and controlling microstructure. From the viewpoint of materials recycling, several properties should be controlled by the latter in simple alloys. Then, observation and evaluation of lattice defects such as vacancy, dislocation and grain boundary are very important for understanding microstructure development during thermo-mechanical treatments. The purpose of this study was to establish a method for esti-mating density of lattice defects in cold rolled and annealed Ti by a precise measurement of electrical resistivity. Pure Ti plates were cold rolled at room temperature. Bar shaped specimens were cut from the plates. Electrical resistivities at 77 K (liquid nitrogen) and 300 K were measured by a direct current four-point method with a constant current of 100 mA. The accuracy of temperature control at 300 K was 0.1 K in silicone oil. Basically the electrical resistivities gradually increased with increasing a reduction of thickness. The density of dislocation was determined to be 2–8 × 10 14 m − 2 in the 15–80% CR specimens","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":"15 1","pages":"18-21"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85354478","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}
Tomotaka Morishita, T. Kaneko, Tsukasa Kashiwabara, R. Hara, S. Wada
We modified a rapid method for determining carbonate content and applied to some iron and steel slags. One gram of pulverized slag sample is weighed into an air-tight plastic bag fitted with stop cock and heat-sealed. The bag is evacuated to remove air, 35 mL of 0.7 mol/L iron(III) chloride and 200 mL of air are introduced through the stop cock and the contents are allowed to react for 20 min with occasional shaking. Carbon dioxide content of the air inside the bag is determined with the aid of carbon dioxide detector tube. The carbonate content of the sample is calculated by summing the amount of carbon dioxide in the air phase and that dissolved in the solution, the latter is calculated by using the Henry’s law. The method was successfully applied to an air aged converter slag sample and samples taken from slag-paved woodland paths. The carbonate content ranged from 0.26 to 0.83 mol/kg. The paving materials that had been exposed to the atmospheric air and soil air contained more carbonate.
本文改进了一种快速测定碳酸盐含量的方法，并将其应用于部分钢铁渣中。将1克矿渣粉样称重装入装有旋塞并热封的气密塑料袋中。抽真空袋中空气，通过旋塞引入35 mL 0.7 mol/L氯化铁(III)和200 mL空气，让内容物反应20分钟，偶尔摇晃。利用二氧化碳检测管测定袋内空气的二氧化碳含量。样品的碳酸盐含量是通过将空气中的二氧化碳量和溶解在溶液中的二氧化碳量相加来计算的，后者是用亨利定律计算的。该方法成功地应用于空气时效转炉炉渣样品和铺有炉渣的林地道路样品。碳酸盐含量为0.26 ~ 0.83 mol/kg。暴露在大气和土壤空气中的铺路材料含有更多的碳酸盐。
{"title":"Determination of Carbonates in Converter Slag by Using Carbon Dioxide Detector Tube","authors":"Tomotaka Morishita, T. Kaneko, Tsukasa Kashiwabara, R. Hara, S. Wada","doi":"10.4144/RPSJ.60.167","DOIUrl":"https://doi.org/10.4144/RPSJ.60.167","url":null,"abstract":"We modified a rapid method for determining carbonate content and applied to some iron and steel slags. One gram of pulverized slag sample is weighed into an air-tight plastic bag fitted with stop cock and heat-sealed. The bag is evacuated to remove air, 35 mL of 0.7 mol/L iron(III) chloride and 200 mL of air are introduced through the stop cock and the contents are allowed to react for 20 min with occasional shaking. Carbon dioxide content of the air inside the bag is determined with the aid of carbon dioxide detector tube. The carbonate content of the sample is calculated by summing the amount of carbon dioxide in the air phase and that dissolved in the solution, the latter is calculated by using the Henry’s law. The method was successfully applied to an air aged converter slag sample and samples taken from slag-paved woodland paths. The carbonate content ranged from 0.26 to 0.83 mol/kg. The paving materials that had been exposed to the atmospheric air and soil air contained more carbonate.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":"47 1","pages":"167-173"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77000709","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}
Vitalievich Gnyloskurenko Svyatoslav, T. Koizumi, K. Kita, Takashi Nakamura
Recent developments in metal foams, especially aluminum, have produced a new class of lightweight materials at the side of the traditional ones such as polymers, ceramics or glass. The combination of a metallic character together with a cellular structure gives an interesting potential for a wide application of this material, particularly for high volume markets such as the automotive industry. Increased demands concerning cost economy, passenger safety in automobiles and materials recycling all bring constructors now to use metal foams. Hereby it provides the additional environmental benefits from a potentially improved fuel economy and lower CO2 emissions. Then, short review of metallic foam was done in the present paper. The possibility of carbonate and hydroxide as foaming agent for Al-Si-Cu alloy by powder metallurgy route is studied, after preparation processes of metallic foams were briefly reviewed in the present paper. It was done by measuring thermal decomposition behavior of foaming agents and evaluating cell structure of those aluminum foams. To obtain fine and homogenous cell structure in powder metallurgy route by using safer carbonate as foaming agent, it has made clear that importance of selecting foaming agent starting decomposition after melting of matrix. It is clearly different from TiH2-foam to grow coarse-rounded cell structure. From this point of view, MgCO3 and CaMg(CO3)2 is suitable for matrix of Al-Si-Cu alloy. CaMg(CO3)2-foam could expand to 1.19 in specific gravity, and keep homogeneous, fine and spherical cell structure.
{"title":"Aluminum Metallic Foams Made by Carbonate Foaming Agents","authors":"Vitalievich Gnyloskurenko Svyatoslav, T. Koizumi, K. Kita, Takashi Nakamura","doi":"10.4144/RPSJ.60.5","DOIUrl":"https://doi.org/10.4144/RPSJ.60.5","url":null,"abstract":"Recent developments in metal foams, especially aluminum, have produced a new class of lightweight materials at the side of the traditional ones such as polymers, ceramics or glass. The combination of a metallic character together with a cellular structure gives an interesting potential for a wide application of this material, particularly for high volume markets such as the automotive industry. Increased demands concerning cost economy, passenger safety in automobiles and materials recycling all bring constructors now to use metal foams. Hereby it provides the additional environmental benefits from a potentially improved fuel economy and lower CO2 emissions. Then, short review of metallic foam was done in the present paper. The possibility of carbonate and hydroxide as foaming agent for Al-Si-Cu alloy by powder metallurgy route is studied, after preparation processes of metallic foams were briefly reviewed in the present paper. It was done by measuring thermal decomposition behavior of foaming agents and evaluating cell structure of those aluminum foams. To obtain fine and homogenous cell structure in powder metallurgy route by using safer carbonate as foaming agent, it has made clear that importance of selecting foaming agent starting decomposition after melting of matrix. It is clearly different from TiH2-foam to grow coarse-rounded cell structure. From this point of view, MgCO3 and CaMg(CO3)2 is suitable for matrix of Al-Si-Cu alloy. CaMg(CO3)2-foam could expand to 1.19 in specific gravity, and keep homogeneous, fine and spherical cell structure.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":"37 1","pages":"5-12"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88594616","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}
Yuta Yamaji, K. Okaya, Gjergj Dodbiba, Li Pang Wang, T. Fujita
Plastics have been used in various applications. The amount of domestic production in 2009 was 1.1 Mt. These days, mechanical recycling for the plastic is required, but one of the biggest problems of this method is how to separate black plastics. Black plastics contain carbon black as a colorant, which make them difficult to be identified by infrared adsorption (IR) spectroscopy. Thus, in this study, we are putting forward Raman spectroscopy for separating plastics (including black plastics) from the discarded appliances. There are reports which indicate that PP, PS, and ABS represent 70–80% of the discarded plastics. Each of them has its own characteristic peaks in Raman spectrum. In case of PP black plastics, nearly 100% of the feed can be identified, however, PS is difficult to be identified when carbon black content is about 3%. ABS of the discarded appliances was not identified. Finally, other fillers such as bromine flame retardants and calcium volume expander did not have any effect on Raman spectrum. In addition, we run some experiments for separating the discarded plastics by means of combining Raman identification with triboelectric separation. In Raman identification, the longer we exposure, the more amount of recovery we got, but grade was the highest in 1.0 s exposure, and it was over 95%. In triboelectric separation, however, the grade of ABS and PS were about 70%.
{"title":"A Novel Separation Method for Plastic of Discarded Appliance Including Black Plastic by Using Raman Spectroscopy","authors":"Yuta Yamaji, K. Okaya, Gjergj Dodbiba, Li Pang Wang, T. Fujita","doi":"10.4144/RPSJ.60.65","DOIUrl":"https://doi.org/10.4144/RPSJ.60.65","url":null,"abstract":"Plastics have been used in various applications. The amount of domestic production in 2009 was 1.1 Mt. These days, mechanical recycling for the plastic is required, but one of the biggest problems of this method is how to separate black plastics. Black plastics contain carbon black as a colorant, which make them difficult to be identified by infrared adsorption (IR) spectroscopy. Thus, in this study, we are putting forward Raman spectroscopy for separating plastics (including black plastics) from the discarded appliances. There are reports which indicate that PP, PS, and ABS represent 70–80% of the discarded plastics. Each of them has its own characteristic peaks in Raman spectrum. In case of PP black plastics, nearly 100% of the feed can be identified, however, PS is difficult to be identified when carbon black content is about 3%. ABS of the discarded appliances was not identified. Finally, other fillers such as bromine flame retardants and calcium volume expander did not have any effect on Raman spectrum. In addition, we run some experiments for separating the discarded plastics by means of combining Raman identification with triboelectric separation. In Raman identification, the longer we exposure, the more amount of recovery we got, but grade was the highest in 1.0 s exposure, and it was over 95%. In triboelectric separation, however, the grade of ABS and PS were about 70%.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":"72 1","pages":"65-71"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87081401","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}
Spent automobile catalyst is an important secondary resource of PGMs but the present recycling technologies require high energy-consumption. It is of much important to enrich the PGMs with some energy saving physical separation methods. This catalyst is usually composed of cordierite lattice which is covered by PGMs bearing coat layer. We adopted heating-quenching process as a pre-treatment of subsequent selective grinding and compositional concentration. It was found that micro-cracks were generated in the coat layer and the interface of the two phases and that some part of the coat layer was detached from the cordierite substrate. This paper analyzes the mechanism of these phenomena by using mathematical calculation and FEM simulation.
{"title":"Separation of PGMs Bearing Alumina Phase from Cordierite in Spent Automobile Catalyst by Thermal Shock","authors":"Gangfeng Liu, Ayumu Tokumaru, S. Owada","doi":"10.4144/RPSJ.60.28","DOIUrl":"https://doi.org/10.4144/RPSJ.60.28","url":null,"abstract":"Spent automobile catalyst is an important secondary resource of PGMs but the present recycling technologies require high energy-consumption. It is of much important to enrich the PGMs with some energy saving physical separation methods. This catalyst is usually composed of cordierite lattice which is covered by PGMs bearing coat layer. We adopted heating-quenching process as a pre-treatment of subsequent selective grinding and compositional concentration. It was found that micro-cracks were generated in the coat layer and the interface of the two phases and that some part of the coat layer was detached from the cordierite substrate. This paper analyzes the mechanism of these phenomena by using mathematical calculation and FEM simulation.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":"16 1","pages":"28-35"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74704489","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}
The authors introduce novel research results on material synthesis and recycling by grinding. The research is focused at first mechanical activation of fine particles of solid material caused by grinding, and this leads to synthesize functional material from two starting materials without heating. One of the examples is to show the formation of complex oxides such as CaTiO 3 from CaO and TiO 2 . Another one is dechlorination of PVC by its grinding with CaO to form CaOHCl and hydrocarbon. This means that it is possible to separate chlorine from PVC by its washing with water. Grinding operation enables us to reduce indium (In) by from indium oxide (In 2 O 3 ) and ITO in the presence of Li 3 N under NH 3 /N 2 gaseous environment. The reaction can be given by: In 2 O 3 + Li 3 N + NH 3 → 2In + 3LiOH + N 2 . The purity of In and its recover are quite high over 90%. Further example of the mechanical activation followed by heating up to about 400 ° C is to generate hydrogen (H 2 ) from biomass such as wood and straw. The biomass is milled with inorganic substance such as CaO, followed by heating at non-oxidative environment. The generation of H 2 in high concentration can be attained during heating, due to adsorption of CO 2 and CO by CaO to form CaCO 3 . This implies that the grinding plays a big role to bring out many possible applications for material synthesis, material and waste processing.
{"title":"Effective Utilization of Grinding and Mechanochemistry to Recycling and Separation","authors":"Qiwu Zhang, J. Kano, F. Saito","doi":"10.4144/RPSJ.60.36","DOIUrl":"https://doi.org/10.4144/RPSJ.60.36","url":null,"abstract":"The authors introduce novel research results on material synthesis and recycling by grinding. The research is focused at first mechanical activation of fine particles of solid material caused by grinding, and this leads to synthesize functional material from two starting materials without heating. One of the examples is to show the formation of complex oxides such as CaTiO 3 from CaO and TiO 2 . Another one is dechlorination of PVC by its grinding with CaO to form CaOHCl and hydrocarbon. This means that it is possible to separate chlorine from PVC by its washing with water. Grinding operation enables us to reduce indium (In) by from indium oxide (In 2 O 3 ) and ITO in the presence of Li 3 N under NH 3 /N 2 gaseous environment. The reaction can be given by: In 2 O 3 + Li 3 N + NH 3 → 2In + 3LiOH + N 2 . The purity of In and its recover are quite high over 90%. Further example of the mechanical activation followed by heating up to about 400 ° C is to generate hydrogen (H 2 ) from biomass such as wood and straw. The biomass is milled with inorganic substance such as CaO, followed by heating at non-oxidative environment. The generation of H 2 in high concentration can be attained during heating, due to adsorption of CO 2 and CO by CaO to form CaCO 3 . This implies that the grinding plays a big role to bring out many possible applications for material synthesis, material and waste processing.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":"27 1","pages":"36-40"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79096762","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}
S. Koyanaka, Takeyoshi Yamamoto, M. Kimura, Kazumasa Yoshida, A. Saitoh
Demand for magnesium alloy parts is expected to increase because of its low density and high specific strength. However, recycling technique for post-consumer magnesium alloy scraps has not been established yet. In particular, low-cost processing for the removal of organic impurities used for painting is needed. In this study, super-heated steam (SHS) treatment was examined as a new technique to remove paint impurities from post-consumer magnesium alloy scraps. As the result, it was found that most of the impurities were easily removed after SHS treatment of 400~410°C and simple mechanical friction.
{"title":"Removal of Paint Impurities from Magnesium Alloy Scraps by Super-heated Steam Treatment","authors":"S. Koyanaka, Takeyoshi Yamamoto, M. Kimura, Kazumasa Yoshida, A. Saitoh","doi":"10.4144/rpsj.60.41","DOIUrl":"https://doi.org/10.4144/rpsj.60.41","url":null,"abstract":"Demand for magnesium alloy parts is expected to increase because of its low density and high specific strength. However, recycling technique for post-consumer magnesium alloy scraps has not been established yet. In particular, low-cost processing for the removal of organic impurities used for painting is needed. In this study, super-heated steam (SHS) treatment was examined as a new technique to remove paint impurities from post-consumer magnesium alloy scraps. As the result, it was found that most of the impurities were easily removed after SHS treatment of 400~410°C and simple mechanical friction.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":"18 1","pages":"41-45"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86306231","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}
Fuel cell hybrids are combination of energy conversion sub-systems—fuel cells and heat engines. Fuel cell hybrids are important for the future as they are currently the most efficient devices when converting chemical energy of methane from renewable fuels to electricity. While the perfect fuel cell would undergo no degradation, practical fuel cells, like batteries, will degrade. This paper is a study of fuel cell hybrids electrochemical performance when the fuel cell sub-system is under- going degradation. In all cases, one can utilize the waste heat to improve overall efficiency through hybridization. Even degradation rates of 0.25 percent per 1000 hours, corresponding to 40,000 hour life, produce significant amounts of waste heat. Power loss is especially high at the cycle end-of- life. Hybridization utilizes waste heat and can be used if degradation occurs and long fuel cell life is expected. The common practice is to linearize degradation. Giving a linear representation to DR, however, gives a linear structure to the area specific resistance, ASR(t). Experimental evidence shows that ASR(t) is commonly an ohmic parabolic function. Degradation rate, DR avg (t), %/1000 hours varies throughout the life of the fuel cell for ohmic parabolic degradation behavior.
{"title":"Evaluation of the Degradation of Fuel Cell Heat Engine Hybrids for Renewable Fuels","authors":"M. Williams, W. Winkler, A. Suzuki, A. Miyamoto","doi":"10.4144/RPSJ.59.155","DOIUrl":"https://doi.org/10.4144/RPSJ.59.155","url":null,"abstract":"Fuel cell hybrids are combination of energy conversion sub-systems—fuel cells and heat engines. Fuel cell hybrids are important for the future as they are currently the most efficient devices when converting chemical energy of methane from renewable fuels to electricity. While the perfect fuel cell would undergo no degradation, practical fuel cells, like batteries, will degrade. This paper is a study of fuel cell hybrids electrochemical performance when the fuel cell sub-system is under- going degradation. In all cases, one can utilize the waste heat to improve overall efficiency through hybridization. Even degradation rates of 0.25 percent per 1000 hours, corresponding to 40,000 hour life, produce significant amounts of waste heat. Power loss is especially high at the cycle end-of- life. Hybridization utilizes waste heat and can be used if degradation occurs and long fuel cell life is expected. The common practice is to linearize degradation. Giving a linear representation to DR, however, gives a linear structure to the area specific resistance, ASR(t). Experimental evidence shows that ASR(t) is commonly an ohmic parabolic function. Degradation rate, DR avg (t), %/1000 hours varies throughout the life of the fuel cell for ohmic parabolic degradation behavior.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":"134 1","pages":"155-161"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74900303","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}
Iron hydroxide works as an adsorbent for some metal ions such as arsenic and selenium and is used as a scavenger. In this study, the removal of fluoride in solution by ferric hydroxide powders has been investigated. Ferric hydroxide powders were prepared by adjusting pH in four kinds of ferric salt solutions to 3.0 followed by filtration and drying. Ferric chloride, ferric nitrate, ferric sulfate and ferric polysulfate were used as ferric salts. All the ferric hydroxide powders removed fluoride ions in the pH range between 6.0 and 7.0. Ferric hydroxide powder formed in ferric polysulfate solution was the most efficient. Sulfuric ion concentration increased with increase in the adsorbed amount of fluoride ions. It is known that sulfate ions adsorb on the surface of ferric hydroxide that precipitate in sulfuric solution. Fluorite ions could be removed by ion exchange with sulfate ions on the surface of ferric hydroxide.
{"title":"Removal of Fluoride Ions from Aqueous Solution Using Ferric Hydroxide","authors":"H. Nakazawa, Kazuhito Nishikawa, Wataru Hareyama","doi":"10.4144/RPSJ.59.67","DOIUrl":"https://doi.org/10.4144/RPSJ.59.67","url":null,"abstract":"Iron hydroxide works as an adsorbent for some metal ions such as arsenic and selenium and is used as a scavenger. In this study, the removal of fluoride in solution by ferric hydroxide powders has been investigated. Ferric hydroxide powders were prepared by adjusting pH in four kinds of ferric salt solutions to 3.0 followed by filtration and drying. Ferric chloride, ferric nitrate, ferric sulfate and ferric polysulfate were used as ferric salts. All the ferric hydroxide powders removed fluoride ions in the pH range between 6.0 and 7.0. Ferric hydroxide powder formed in ferric polysulfate solution was the most efficient. Sulfuric ion concentration increased with increase in the adsorbed amount of fluoride ions. It is known that sulfate ions adsorb on the surface of ferric hydroxide that precipitate in sulfuric solution. Fluorite ions could be removed by ion exchange with sulfate ions on the surface of ferric hydroxide.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":"1 1","pages":"67-72"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89163155","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}
Yuka Suzaki, M. Ueda, M. Ikeda, K. Doi, Terauchi Shuntaro
Porous titanium is an excellent biomaterial candidate because of its ability to maintain appropriate strength once it is implanted. The osteointegration of titanium and its alloys is less than that of bioactive ceramics. Therefore, various surface modification techniques have been developed to improve the osteointegration. We successfully prepared titanium dioxide (TiO2) and calcium titanate (CaTiO3) films on the surfaces of pure Ti by combined chemical-hydrothermal treatment. Especially in CaTiO3, the formation of apatite was promoted due to the release of Ca 2+ from the surface of CaTiO3 in Hanks’ solution. Calcite (CaCO3) is a biodegradable material that must enhance hydroxyapatite (HAp) formation in simulated body fluid as well as in CaTiO3. The purpose of the present study was to synthesize bioactive films including CaCO3 on pure Ti substrates and porous titanium by chemical-hydrothermal treatment using Ca(OH)2 and KHCO3. The modified porous materials were tested mechanically in a compression test. CaTiO3-CaCO3 and TiO2-CaCO3 films were synthesized by choosing an ion concentration ratio of CO3 /Ca in the aqueous solution for hydrothermal treatment. CaTiO3-CaCO3 films were also synthesized on porous titanium by hydrothermal treatment. Compressive properties of porous titanium after the treatment were similar to those prior to the treatment. The films produced by the present surface modification showed no significant changes compared to the original properties.
{"title":"Hydrothermal Synthesis of Bioactive Titanium Oxide-CaCO3 Films with Aqueous Ca(OH)2/KHCO3 on Pure Ti","authors":"Yuka Suzaki, M. Ueda, M. Ikeda, K. Doi, Terauchi Shuntaro","doi":"10.4144/RPSJ.59.22","DOIUrl":"https://doi.org/10.4144/RPSJ.59.22","url":null,"abstract":"Porous titanium is an excellent biomaterial candidate because of its ability to maintain appropriate strength once it is implanted. The osteointegration of titanium and its alloys is less than that of bioactive ceramics. Therefore, various surface modification techniques have been developed to improve the osteointegration. We successfully prepared titanium dioxide (TiO2) and calcium titanate (CaTiO3) films on the surfaces of pure Ti by combined chemical-hydrothermal treatment. Especially in CaTiO3, the formation of apatite was promoted due to the release of Ca 2+ from the surface of CaTiO3 in Hanks’ solution. Calcite (CaCO3) is a biodegradable material that must enhance hydroxyapatite (HAp) formation in simulated body fluid as well as in CaTiO3. The purpose of the present study was to synthesize bioactive films including CaCO3 on pure Ti substrates and porous titanium by chemical-hydrothermal treatment using Ca(OH)2 and KHCO3. The modified porous materials were tested mechanically in a compression test. CaTiO3-CaCO3 and TiO2-CaCO3 films were synthesized by choosing an ion concentration ratio of CO3 /Ca in the aqueous solution for hydrothermal treatment. CaTiO3-CaCO3 films were also synthesized on porous titanium by hydrothermal treatment. Compressive properties of porous titanium after the treatment were similar to those prior to the treatment. The films produced by the present surface modification showed no significant changes compared to the original properties.","PeriodicalId":20971,"journal":{"name":"Resources Processing","volume":"3 1","pages":"22-26"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89305241","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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