A process was proposed to convert and separate selenium and arsenic in copper anode slime(CAS) by low-temperature alkali fusion process.Central composite design was employed to optimize the effective parameters,in whi...A process was proposed to convert and separate selenium and arsenic in copper anode slime(CAS) by low-temperature alkali fusion process.Central composite design was employed to optimize the effective parameters,in which Na OH/CAS mass ratio,fusion temperature and fusion time were selected as variables,and the conversion ratio of selenium and arsenic as responses.Second-order polynomial models of high significance and 3D response surface plots were constructed to show the relationship between the responses and the variables.Optimum area of >90% selenium conversion ratio and >90% arsenic conversion ratio was obtained by the overlaid contours at Na OH/CAS mass ratio of 0.65-0.75,fusion temperature of 803-823 K and fusion time of 20-30 min.The models are validated by experiments in the optimum area,and the results demonstrate that these models are reliable and accurate in predicting the fusion process.展开更多
An inorganic cation exchanger, zeolitic material, was synthesized from dehydrated cake, which was discharged from recycling of construction waste soil, using the alkali fusion method. The waste clay was mixed with NaO...An inorganic cation exchanger, zeolitic material, was synthesized from dehydrated cake, which was discharged from recycling of construction waste soil, using the alkali fusion method. The waste clay was mixed with NaOH powder (the weight ratio of NaOH/waste clay = 1.0) and then heated at 300°C for 1 h to make a fused material. This fused material was then added to distilled water, and then heated at 90°C, 120°C, 150°C and 180°C for 12 h in reaction bombs under autogenous pressure in order to synthesize the cation exchanger. As a result, waste cake can be converted into fused material with high solubility, and zeolitic materials can be synthesized from the fused material. A mixture of zeolite-X and hydroxysodalite was synthesized at 90°C and 120°C, hydroxysodalite alone was synthesized at 150°C and 180°C. By increasing the synthesis temperature, the cation exchange capacity (CEC) of the product decreased, and the highest CEC of the product at 90°C, including zeolite-X, was 2.06 mmol/g, which is 64.3% of commercial zeolite-13X (3.2 mmol/g).展开更多
In this work,a two-step zircon method to produce zirconium oxychloride was introduced,and the alkali fusion technique with NaOH and water leaching process were investigated.The effects of the operating conditions on t...In this work,a two-step zircon method to produce zirconium oxychloride was introduced,and the alkali fusion technique with NaOH and water leaching process were investigated.The effects of the operating conditions on the decomposition of zircon were determined,and the optimal conditions are as follows:alkali/zircon mass ratio of 0.7 at the first step and 0.6 at the second step(0.7+0.6),fusion temperature of 700℃and fusion time of 0.5 h at the first step and 0.5 h at the second step(0.5+0.5 h).Under these conditions,the decomposition alloy of zircon sand can reach 97.25%.In the fusion process of zircon sand,the products of first step are mainly Na2ZrO3 and ZrSiO4,the products of second step are Na2ZrO3 and Na2SiO3,and the diffraction peaks of Na2ZrSiO5 are not observed.The conditions of water leaching process were investigated as well,and the optimal conditions are as follows:liquid-solid ratio of 5:1,leaching time of 0.5 h,leaching temperature of 50℃and leaching three times.Under these conditions,the contents of leaching products SiO2 and Na2O are 3.51%(40%ZrO2)and 4.46%(40%ZrO2),respectively.The crystal phase structures of Na2ZrO3 and Na2SiO3 are formed in water leaching process.展开更多
为解决常规金属元素分析中存在的成本高、盐分高、难脱离、不稳定等问题,实现土壤样品快速高效分析检测,通过探讨了容器种类、熔剂用量、熔样温度及时间对准确性的影响,以较低价镍坩埚为容器、1.5 g NaOH为熔剂,采用低温短时碱熔法(700...为解决常规金属元素分析中存在的成本高、盐分高、难脱离、不稳定等问题,实现土壤样品快速高效分析检测,通过探讨了容器种类、熔剂用量、熔样温度及时间对准确性的影响,以较低价镍坩埚为容器、1.5 g NaOH为熔剂,采用低温短时碱熔法(700℃,15 min)与热溶法进行样品前处理,电感耦合等离子体发射光谱仪进行检测,建立了低盐低成本碱熔-电感耦合等离子体发射光谱(ICP-OES)法同时测定土壤中铁铝锰钡的方法。方法学研究表明,在仪器最佳测定条件下,Al_(2)O_(3)、Fe_(2)O_(3)、Ba、Mn的检出限分别为0.03%、0.01%、0.01 mg/kg、0.01 mg/kg,相对标准偏差在0.57%~2.7%,且成本低、盐分少、易脱离、稳定性好,结果准确可靠,适用于土壤中金属元素的测定。展开更多
基金Project(51234009)supported by the National Natural Science Foundation of ChinaProject(2014DFA90520)supported by International Cooperation Program of Ministry of Science of ChinaProject(2013A100003)supported by the Production,Teaching and Research Program of Guangdong Province,China
文摘A process was proposed to convert and separate selenium and arsenic in copper anode slime(CAS) by low-temperature alkali fusion process.Central composite design was employed to optimize the effective parameters,in which Na OH/CAS mass ratio,fusion temperature and fusion time were selected as variables,and the conversion ratio of selenium and arsenic as responses.Second-order polynomial models of high significance and 3D response surface plots were constructed to show the relationship between the responses and the variables.Optimum area of >90% selenium conversion ratio and >90% arsenic conversion ratio was obtained by the overlaid contours at Na OH/CAS mass ratio of 0.65-0.75,fusion temperature of 803-823 K and fusion time of 20-30 min.The models are validated by experiments in the optimum area,and the results demonstrate that these models are reliable and accurate in predicting the fusion process.
文摘An inorganic cation exchanger, zeolitic material, was synthesized from dehydrated cake, which was discharged from recycling of construction waste soil, using the alkali fusion method. The waste clay was mixed with NaOH powder (the weight ratio of NaOH/waste clay = 1.0) and then heated at 300°C for 1 h to make a fused material. This fused material was then added to distilled water, and then heated at 90°C, 120°C, 150°C and 180°C for 12 h in reaction bombs under autogenous pressure in order to synthesize the cation exchanger. As a result, waste cake can be converted into fused material with high solubility, and zeolitic materials can be synthesized from the fused material. A mixture of zeolite-X and hydroxysodalite was synthesized at 90°C and 120°C, hydroxysodalite alone was synthesized at 150°C and 180°C. By increasing the synthesis temperature, the cation exchange capacity (CEC) of the product decreased, and the highest CEC of the product at 90°C, including zeolite-X, was 2.06 mmol/g, which is 64.3% of commercial zeolite-13X (3.2 mmol/g).
基金financially supported by the National Science Foundation for Distinguished Young Scholars of China(No.51125018)
文摘In this work,a two-step zircon method to produce zirconium oxychloride was introduced,and the alkali fusion technique with NaOH and water leaching process were investigated.The effects of the operating conditions on the decomposition of zircon were determined,and the optimal conditions are as follows:alkali/zircon mass ratio of 0.7 at the first step and 0.6 at the second step(0.7+0.6),fusion temperature of 700℃and fusion time of 0.5 h at the first step and 0.5 h at the second step(0.5+0.5 h).Under these conditions,the decomposition alloy of zircon sand can reach 97.25%.In the fusion process of zircon sand,the products of first step are mainly Na2ZrO3 and ZrSiO4,the products of second step are Na2ZrO3 and Na2SiO3,and the diffraction peaks of Na2ZrSiO5 are not observed.The conditions of water leaching process were investigated as well,and the optimal conditions are as follows:liquid-solid ratio of 5:1,leaching time of 0.5 h,leaching temperature of 50℃and leaching three times.Under these conditions,the contents of leaching products SiO2 and Na2O are 3.51%(40%ZrO2)and 4.46%(40%ZrO2),respectively.The crystal phase structures of Na2ZrO3 and Na2SiO3 are formed in water leaching process.
