The leaching of magnesium from desiliconization slag of nickel laterite ores by carbonation process was studied.The influence of various parameters was investigated to optimize the conditions and determine the kinetic...The leaching of magnesium from desiliconization slag of nickel laterite ores by carbonation process was studied.The influence of various parameters was investigated to optimize the conditions and determine the kinetics of the reaction.The results show that with increasing stirring speed,liquid-to-solid ratio and reaction time,and decreasing temperature,the leaching rate of magnesium enhances.The leaching process of the desiliconization slag in the range of 288-298 K is controlled by the surface chemical reaction model.The apparent activation energy is-20.45 kJ/mol,and the kinetics model is obtained.展开更多
The application of microwave technique in the hydrometallurgy of nickel laterite ores was described.The mixture of nickel laterite ores and sulfuric acid was pre-treated by microwave irradiation.The dissolving of nick...The application of microwave technique in the hydrometallurgy of nickel laterite ores was described.The mixture of nickel laterite ores and sulfuric acid was pre-treated by microwave irradiation.The dissolving of nickel was conducted in hot water at the atmospheric pressure.The effects of factors,such as microwave power,microwave irradiation time,and sulfuric acid dosage, were investigated.In microwave field,the migration of ionic species and/or rotation of dipolar species promote the liquid?solid reaction process due to the increased contact area of reactants and leaching reaction rate constant.Thanks to the strengthening action of microwave,the microwave-assisted leaching process has its advantages,such as higher extracting rate than conventional atmospheric leaching,and no need for high-pressure operation as high pressure acid leaching(HPAL).The ferric iron in leaching solution could be effectively removed by sodium jarosite process with a little loss of nickel in the jarosite precipitate.展开更多
Dissolution kinetics of nickel from lateritic ore in nitric acid solution was investigated. Experimental parameters used were stirring speed(100-600 r/min), temperature(40-96 °C), nitric acid concentration(0.1-2 ...Dissolution kinetics of nickel from lateritic ore in nitric acid solution was investigated. Experimental parameters used were stirring speed(100-600 r/min), temperature(40-96 °C), nitric acid concentration(0.1-2 mol/L) and particle size(<106 μm). The shrinking core model was applied to the results of experiments investigating the effects of leaching temperature in the range of 40-90 °C and nitric acid concentration in range of 0.1-2 mol/L on nickel dissolution rate. The kinetic analysis shows that the nickel dissolution from lateritic ore could be described by diffusion model. The activation energy(E_a) for the dissolution reaction is calculated as 79.52 kJ/mol.展开更多
A chemical precipitation-thermal decomposition method was developed to synthesize Co3O4 nanoparticles using cobalt liquor obtained from the atmospheric pressure acid leaching process of nickel laterite ores. The effec...A chemical precipitation-thermal decomposition method was developed to synthesize Co3O4 nanoparticles using cobalt liquor obtained from the atmospheric pressure acid leaching process of nickel laterite ores. The effects of the precursor reaction temperature, the concentration of Co2+, and the calcination temperature on the specific surface area, morphology, and the electrochemical behavior of the ob- tained Co304 particles were investigated. The precursor basic cobaltous carbonate and cobaltosic oxide products were characterized and ana- lyzed by Fourier transform infrared spectroscopy, thermogravimetric differential thermal analysis, X-ray diffraction, field-emission scanning electron microscopy, specific surface area analysis, and electrochemical analysis. The results indicate that the specific surface area of the Co3O4particles with a diameter of 30 rim, which were obtained under the optimum conditions of a precursor reaction temperature of 30℃, 0.25 mol/L Co2+, and a calcination temperature of 350℃, was 48.89 m2/g. Electrodes fabricated using Co3O4 nanoparticles exhibited good electrochemical properties, with a specific capacitance of 216.3 F/g at a scan rate of 100 mV/s.展开更多
基金Project(2007CB613603)supported by the National Basic Research Program of China
文摘The leaching of magnesium from desiliconization slag of nickel laterite ores by carbonation process was studied.The influence of various parameters was investigated to optimize the conditions and determine the kinetics of the reaction.The results show that with increasing stirring speed,liquid-to-solid ratio and reaction time,and decreasing temperature,the leaching rate of magnesium enhances.The leaching process of the desiliconization slag in the range of 288-298 K is controlled by the surface chemical reaction model.The apparent activation energy is-20.45 kJ/mol,and the kinetics model is obtained.
基金Project(50774020)supported by the National Natural Science Foundation of China
文摘The application of microwave technique in the hydrometallurgy of nickel laterite ores was described.The mixture of nickel laterite ores and sulfuric acid was pre-treated by microwave irradiation.The dissolving of nickel was conducted in hot water at the atmospheric pressure.The effects of factors,such as microwave power,microwave irradiation time,and sulfuric acid dosage, were investigated.In microwave field,the migration of ionic species and/or rotation of dipolar species promote the liquid?solid reaction process due to the increased contact area of reactants and leaching reaction rate constant.Thanks to the strengthening action of microwave,the microwave-assisted leaching process has its advantages,such as higher extracting rate than conventional atmospheric leaching,and no need for high-pressure operation as high pressure acid leaching(HPAL).The ferric iron in leaching solution could be effectively removed by sodium jarosite process with a little loss of nickel in the jarosite precipitate.
基金supported by The Research Foundation of the Selcuk University under the Project No:06101021
文摘Dissolution kinetics of nickel from lateritic ore in nitric acid solution was investigated. Experimental parameters used were stirring speed(100-600 r/min), temperature(40-96 °C), nitric acid concentration(0.1-2 mol/L) and particle size(<106 μm). The shrinking core model was applied to the results of experiments investigating the effects of leaching temperature in the range of 40-90 °C and nitric acid concentration in range of 0.1-2 mol/L on nickel dissolution rate. The kinetic analysis shows that the nickel dissolution from lateritic ore could be described by diffusion model. The activation energy(E_a) for the dissolution reaction is calculated as 79.52 kJ/mol.
基金financially supported by the National Science Foundation for Distinguished Young Scholars of China(No.51125018)the National Key Technologies R&D Program(2011BAC06B07)+2 种基金the Key Research Program of the Chinese Academy of Sciences(No.KGZD-EW-201-2)the National Natural Science Foundation of China(No.51204153)the Program of Jiangsu Collaborative Innovation Center for Ecological Building Materials and Environmental Protection Equipments(No.YCXT201610)
文摘A chemical precipitation-thermal decomposition method was developed to synthesize Co3O4 nanoparticles using cobalt liquor obtained from the atmospheric pressure acid leaching process of nickel laterite ores. The effects of the precursor reaction temperature, the concentration of Co2+, and the calcination temperature on the specific surface area, morphology, and the electrochemical behavior of the ob- tained Co304 particles were investigated. The precursor basic cobaltous carbonate and cobaltosic oxide products were characterized and ana- lyzed by Fourier transform infrared spectroscopy, thermogravimetric differential thermal analysis, X-ray diffraction, field-emission scanning electron microscopy, specific surface area analysis, and electrochemical analysis. The results indicate that the specific surface area of the Co3O4particles with a diameter of 30 rim, which were obtained under the optimum conditions of a precursor reaction temperature of 30℃, 0.25 mol/L Co2+, and a calcination temperature of 350℃, was 48.89 m2/g. Electrodes fabricated using Co3O4 nanoparticles exhibited good electrochemical properties, with a specific capacitance of 216.3 F/g at a scan rate of 100 mV/s.