An experimental investigation was presented on the separation of Cu（Ⅱ）, Zn（Ⅱ）, and Cd（Ⅱ） from a rich sulfate leachate of zinc slag by solvent extraction. The results of orthogonal experiments indicate that LI...An experimental investigation was presented on the separation of Cu（Ⅱ）, Zn（Ⅱ）, and Cd（Ⅱ） from a rich sulfate leachate of zinc slag by solvent extraction. The results of orthogonal experiments indicate that LIX 984N is highly selective and very efficient in the extraction of Cu（Ⅱ）, and the analysis of variance indicates that the sequence of parameters according to their influence on the separation efficiency is phase ratio 〉 LIX 984N concentration 〉 pH value 〉 extraction time. The optimal condition for copper extraction is obtained as 25% of LIX 984N concentration, 7 rain of extraction time, 3：2 of phase ratio O/A, and pH = 1.7. The separation of Zn（Ⅱ） and Cd（Ⅱ） was performed after the copper extraction from the raffinate. Comparative analysis of the separation with di-2-ethylhexyl phosphoric acid （D2EHPA）, D2EHPA-tributyl- phosophate （TBP） synergistic extracting system, and 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester （HEHEHP） was made at pH = 2.0. It is demonstrated that the extraction efficiency with D2EHPA is improved after being saponified by sodium hydroxide, and D2EHPA-TBP synergistic extracting, as well as HEHEHP, has a superior selectivity to Zn（Ⅱ） over Cd（Ⅱ）.展开更多
The acid leaching,ferric leaching,and bioleaching of chalcocite and pyrite minerals were conducted in two sets of 3L stirred reactors.The dissolution rates of copper and iron were correlated with leaching conditions.I...The acid leaching,ferric leaching,and bioleaching of chalcocite and pyrite minerals were conducted in two sets of 3L stirred reactors.The dissolution rates of copper and iron were correlated with leaching conditions.In the acid leaching process,the dissolution rate of chalcocite was around 40wt.% while that of pyrite was less than 4%.In the ferric leaching process with high ferric concentration,only 10 wt.% of iron in pyrite was leached out at the same retention time though the copper recovery over 60 wt.% in chalcocite.For the bioleaching process,the chalcocite leaching rate was highly increased,nearly 90 wt.% of copper was leached out,and the iron dissolution of pyrite exceeded 70 wt.%.For the two minerals,the bioleaching shows the highest leaching rate compared with the acid leaching or ferric leaching.In uncontrolled bioleaching process,pyrite could be dissolved effectively.The experimental data were fitted to the shrinking core and particle model.The results show that in all the leaching tests,the chalcocite leaching was mainly controlled by diffusion,while for the pyrite leaching,chemical reaction is the main rate-determining step.展开更多
文摘An experimental investigation was presented on the separation of Cu（Ⅱ）, Zn（Ⅱ）, and Cd（Ⅱ） from a rich sulfate leachate of zinc slag by solvent extraction. The results of orthogonal experiments indicate that LIX 984N is highly selective and very efficient in the extraction of Cu（Ⅱ）, and the analysis of variance indicates that the sequence of parameters according to their influence on the separation efficiency is phase ratio 〉 LIX 984N concentration 〉 pH value 〉 extraction time. The optimal condition for copper extraction is obtained as 25% of LIX 984N concentration, 7 rain of extraction time, 3：2 of phase ratio O/A, and pH = 1.7. The separation of Zn（Ⅱ） and Cd（Ⅱ） was performed after the copper extraction from the raffinate. Comparative analysis of the separation with di-2-ethylhexyl phosphoric acid （D2EHPA）, D2EHPA-tributyl- phosophate （TBP） synergistic extracting system, and 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester （HEHEHP） was made at pH = 2.0. It is demonstrated that the extraction efficiency with D2EHPA is improved after being saponified by sodium hydroxide, and D2EHPA-TBP synergistic extracting, as well as HEHEHP, has a superior selectivity to Zn（Ⅱ） over Cd（Ⅱ）.
基金financially by the Major State Basic Research Development Program of China (No.2004CB619206)the Natural Science Foundation of Fujian Province,China (No.2010J05158)
文摘The acid leaching,ferric leaching,and bioleaching of chalcocite and pyrite minerals were conducted in two sets of 3L stirred reactors.The dissolution rates of copper and iron were correlated with leaching conditions.In the acid leaching process,the dissolution rate of chalcocite was around 40wt.% while that of pyrite was less than 4%.In the ferric leaching process with high ferric concentration,only 10 wt.% of iron in pyrite was leached out at the same retention time though the copper recovery over 60 wt.% in chalcocite.For the bioleaching process,the chalcocite leaching rate was highly increased,nearly 90 wt.% of copper was leached out,and the iron dissolution of pyrite exceeded 70 wt.%.For the two minerals,the bioleaching shows the highest leaching rate compared with the acid leaching or ferric leaching.In uncontrolled bioleaching process,pyrite could be dissolved effectively.The experimental data were fitted to the shrinking core and particle model.The results show that in all the leaching tests,the chalcocite leaching was mainly controlled by diffusion,while for the pyrite leaching,chemical reaction is the main rate-determining step.
