Aluminum was leached out from coal fly ash by pressure acid-leaching method. The effects of coal fly ash size, sulfuric acid concentration, reaction time and reaction temperature on extraction efficiency of aluminum w...Aluminum was leached out from coal fly ash by pressure acid-leaching method. The effects of coal fly ash size, sulfuric acid concentration, reaction time and reaction temperature on extraction efficiency of aluminum were investigated comprehensively. The phase and morphology of coal fly ash and solid residues after reaction were analyzed by XRD, SEM and IR. The optimal technological conditions for extracting aluminum from coal fly ash were eventually confirmed that coal fly ash with size of 74 μm and sulfuric acid with concentration of 50% are mixed in pressure reaction kettle to react for 4 h at 180 ℃. Under the optimal conditions, the extraction efficiency of aluminum can reach 82.4%.展开更多
The leaching performance and leaching kinetics of LiFePO_(4)(LFP)and Al in Al-bearing spent LFP cathode powder were systematically studied.The effects of temperature(273−368 K),stirring speed(200−950 r/min),reaction t...The leaching performance and leaching kinetics of LiFePO_(4)(LFP)and Al in Al-bearing spent LFP cathode powder were systematically studied.The effects of temperature(273−368 K),stirring speed(200−950 r/min),reaction time(0−240 min),acid-to-material ratio(0.1:1−1:1 mL/g)and liquid-to-solid ratio(3:1−9:1 mL/g)on the leaching process were investigated.The results show that the concentration of reactants and the temperature have a greater impact on the leaching of Al.Under the optimal conditions,leaching efficiencies of LFP and Al are 91.53%and 15.98%,respectively.The kinetic study shows that the leaching of LFP is kinetically controlled by mixed surface reaction and diffusion,with an activation energy of 22.990 kJ/mol;whereas the leaching of Al is only controlled by surface chemical reaction,with an activation energy of 46.581 kJ/mol.A low leaching temperature can effectively suppress the dissolving of Al during the acid leaching of the spent LFP cathode material.展开更多
Aluminum recovery is a key issue for the overall recycling of valuable metals from spent catalysts. This paper focuses on the recovery and regeneration of alumina with high additional value from the spent hydrodesulfu...Aluminum recovery is a key issue for the overall recycling of valuable metals from spent catalysts. This paper focuses on the recovery and regeneration of alumina with high additional value from the spent hydrodesulfurization catalyst CoMo/Al_2O_3. The results indicate that 98.13% alumina is successfully leached from the treated spent catalysts by an alkaline leaching process under the conditions of 5 mol·L^(-1) sodium hydroxide,a liquid/solid ratio of 20 ml·g^(-1),a temperature of 160 0 C and a reaction time of 4 h. In the leaching residue, no difficult leaching compound is found and cobalt and nickel are enriched,both of which are conducive to the subsequent metal recovery step. The reaction order of aluminum leaching is 0.99. This reaction fits well with the interfacial chemical reaction model, and its apparent activation energy is calculated as 45.50 kJ mol^(-1). Subsequently, y-Al_2O_3 with a high specific surface area of 278.3 m^2·g^(-1), a mean size of 2.2 μm and an average pore size of 3.10 nm is then regenerated from the lixivium, indicating its suitability for use as a catalyst carrier. The recovery and regeneration of alumina from spent catalysts can not only significantly contribute to the total recycling of such hazardous spent catalysts but also provide a new approach for the preparation of y-Al_2O_3 with a high specific surface area using spent catalysts as the aluminum sources.展开更多
基金Project (BO210(2008)) supported by the Foundation of "Hundred Talent Program" of Chinese Academic of SciencesProject (2008-G-158) supported by the Scientific and Technological Project of Qinghai Province, China
文摘Aluminum was leached out from coal fly ash by pressure acid-leaching method. The effects of coal fly ash size, sulfuric acid concentration, reaction time and reaction temperature on extraction efficiency of aluminum were investigated comprehensively. The phase and morphology of coal fly ash and solid residues after reaction were analyzed by XRD, SEM and IR. The optimal technological conditions for extracting aluminum from coal fly ash were eventually confirmed that coal fly ash with size of 74 μm and sulfuric acid with concentration of 50% are mixed in pressure reaction kettle to react for 4 h at 180 ℃. Under the optimal conditions, the extraction efficiency of aluminum can reach 82.4%.
基金The authors acknowledge the funding support from the Key Deployment Projects of Chinese Academy of Sciences(ZDRW_CN_2020-1)the Sino-German Cooperation Research Project under the Natural Science Foundation of China(51761135108)+1 种基金the German Research Foundation(392417756)the CAS Interdisciplinary Innovation Team.
文摘The leaching performance and leaching kinetics of LiFePO_(4)(LFP)and Al in Al-bearing spent LFP cathode powder were systematically studied.The effects of temperature(273−368 K),stirring speed(200−950 r/min),reaction time(0−240 min),acid-to-material ratio(0.1:1−1:1 mL/g)and liquid-to-solid ratio(3:1−9:1 mL/g)on the leaching process were investigated.The results show that the concentration of reactants and the temperature have a greater impact on the leaching of Al.Under the optimal conditions,leaching efficiencies of LFP and Al are 91.53%and 15.98%,respectively.The kinetic study shows that the leaching of LFP is kinetically controlled by mixed surface reaction and diffusion,with an activation energy of 22.990 kJ/mol;whereas the leaching of Al is only controlled by surface chemical reaction,with an activation energy of 46.581 kJ/mol.A low leaching temperature can effectively suppress the dissolving of Al during the acid leaching of the spent LFP cathode material.
基金financially supported by the National Natural Science Commission-Yunnan Joint Fund Project (No.U1402274)
文摘Aluminum recovery is a key issue for the overall recycling of valuable metals from spent catalysts. This paper focuses on the recovery and regeneration of alumina with high additional value from the spent hydrodesulfurization catalyst CoMo/Al_2O_3. The results indicate that 98.13% alumina is successfully leached from the treated spent catalysts by an alkaline leaching process under the conditions of 5 mol·L^(-1) sodium hydroxide,a liquid/solid ratio of 20 ml·g^(-1),a temperature of 160 0 C and a reaction time of 4 h. In the leaching residue, no difficult leaching compound is found and cobalt and nickel are enriched,both of which are conducive to the subsequent metal recovery step. The reaction order of aluminum leaching is 0.99. This reaction fits well with the interfacial chemical reaction model, and its apparent activation energy is calculated as 45.50 kJ mol^(-1). Subsequently, y-Al_2O_3 with a high specific surface area of 278.3 m^2·g^(-1), a mean size of 2.2 μm and an average pore size of 3.10 nm is then regenerated from the lixivium, indicating its suitability for use as a catalyst carrier. The recovery and regeneration of alumina from spent catalysts can not only significantly contribute to the total recycling of such hazardous spent catalysts but also provide a new approach for the preparation of y-Al_2O_3 with a high specific surface area using spent catalysts as the aluminum sources.
