Chalcopyrite is one of the most important copper minerals;however,the extracted efficiency of chalcopyrite is still not satisfactory in hydrometallurgy owing to its high lattice energy which leads to its low dissoluti...Chalcopyrite is one of the most important copper minerals;however,the extracted efficiency of chalcopyrite is still not satisfactory in hydrometallurgy owing to its high lattice energy which leads to its low dissolution kinetics.To overcome the difficulties,many advanced technologies have been developed,including the selection of high effectively bacteria,the inhibition of the passivation film adhered onto the minerals surface,and the maintenance of solution redox potential under an optimum range.Up to date,considerable researches on the first two terms have been summarized,while the overview of the last term has been rarely reported.Based on corresponding works in recent years,key trends and roles of solution redox potential in copper hydrometallurgy,including its definition,effect and maintenance,have been introduced in this review.展开更多
In order to utilize low-grade manganese ore resources effectively, a hydrometallurgical process was developed for manganese extraction in dilute sulfuric acid medium, and the kinetics of leaching manga- nese was also ...In order to utilize low-grade manganese ore resources effectively, a hydrometallurgical process was developed for manganese extraction in dilute sulfuric acid medium, and the kinetics of leaching manga- nese was also investigated. At room temperature, manganese from low-grade manganese carbonate ores was extracted by sulfuric acid leaching without reductants. During the extracting process, single-factor analysis method was used to evaluate the effects of grinding fineness, sulfuric acid concentration, liquid-to-solid ratio, agitation rate and leaching time on the leaching efficiencies of Mn and Fe. The optimal leaching conditions are determined as coarse particles of below 2 mm size （without ball-milling）, sulfuric acid concentration of 0.86 mol/L, liquid-to-solid ratio of 5：1, agitation rate of 150 r/rain and leaching for 180 min at room temperature. Under the optimal conditions, the leaching efficiencies of Mn and Fe are 96.21g and 13.35%, respectively. In addition, through the experiments at different temper- atures, it is found that the leaching process follows the shrinking core model under the conditions of changing acid concentration and intermittent reaction device. Moreover, the apparent activations of effective diffusion and chemical reaction in the kinetic model are calculated to be 18.83 and 27.15 kJ/mol, respectively.展开更多
基金Projects(51774332,U1932129,51804350,51934009)supported by the National Natural Science Foundation of ChinaProject(2018JJ1041)supported by the Natural Science Foundation of Hunan Province,China。
文摘Chalcopyrite is one of the most important copper minerals;however,the extracted efficiency of chalcopyrite is still not satisfactory in hydrometallurgy owing to its high lattice energy which leads to its low dissolution kinetics.To overcome the difficulties,many advanced technologies have been developed,including the selection of high effectively bacteria,the inhibition of the passivation film adhered onto the minerals surface,and the maintenance of solution redox potential under an optimum range.Up to date,considerable researches on the first two terms have been summarized,while the overview of the last term has been rarely reported.Based on corresponding works in recent years,key trends and roles of solution redox potential in copper hydrometallurgy,including its definition,effect and maintenance,have been introduced in this review.
基金the Key Laboratory of Resources of Nonferrous Metals Ministry of Education (Central South University) for the laboratories and financial support
文摘In order to utilize low-grade manganese ore resources effectively, a hydrometallurgical process was developed for manganese extraction in dilute sulfuric acid medium, and the kinetics of leaching manga- nese was also investigated. At room temperature, manganese from low-grade manganese carbonate ores was extracted by sulfuric acid leaching without reductants. During the extracting process, single-factor analysis method was used to evaluate the effects of grinding fineness, sulfuric acid concentration, liquid-to-solid ratio, agitation rate and leaching time on the leaching efficiencies of Mn and Fe. The optimal leaching conditions are determined as coarse particles of below 2 mm size （without ball-milling）, sulfuric acid concentration of 0.86 mol/L, liquid-to-solid ratio of 5：1, agitation rate of 150 r/rain and leaching for 180 min at room temperature. Under the optimal conditions, the leaching efficiencies of Mn and Fe are 96.21g and 13.35%, respectively. In addition, through the experiments at different temper- atures, it is found that the leaching process follows the shrinking core model under the conditions of changing acid concentration and intermittent reaction device. Moreover, the apparent activations of effective diffusion and chemical reaction in the kinetic model are calculated to be 18.83 and 27.15 kJ/mol, respectively.
