The solvent extraction of copper and zinc from the bioleaching solutions of low-grade sulfide ores with LIX984 and D2EHPA was investigated. The influences of extractant content, aqueous pH value, phase ratio and (equi...The solvent extraction of copper and zinc from the bioleaching solutions of low-grade sulfide ores with LIX984 and D2EHPA was investigated. The influences of extractant content, aqueous pH value, phase ratio and (equilibration) time on metals extraction were studied. The results show that LIX984 has a higher selectivity for copper than for iron, zinc and other metals, and has the copper extraction rate above 97%, while the zinc and iron extraction rate is less than 1.6% respectively. Zinc extraction is carried out following the copper extraction from the raffinate. The zinc extraction with di(2-ethylhexyl) phosphoric acid(D2EHPA) is low due to its poor cation exchange. A sodium salt of D2EHPA is used and the zinc extraction rate is enhanced to above 98%. Though iron (Ⅲ) is strongly extracted before the extraction of zinc by D2EHPA, it is difficult to strip iron from the organic phase by sulfuric acid. The zinc stripping rate is above 99% with 100g/L sulfuric acid, while that of iron is 0.16%. Hence, the separation of zinc from iron can be achieved by the selective stripping.展开更多
The organic phase separated from the interfacial crud provided by Dexing copper mine in Jiangxi, China, was analyzed by combined gas chromatography-mass spectroscopy. The results show that many kinds of emphiphiles co...The organic phase separated from the interfacial crud provided by Dexing copper mine in Jiangxi, China, was analyzed by combined gas chromatography-mass spectroscopy. The results show that many kinds of emphiphiles containing such hydrophilic groups as carbonyl, carboxyl, sulphonyl or acylamine exist in organic phase. Conclusively, Lix984N would degrade gradually during a long-term contact with the acidic aqueous feed and strip reagents. Lix84 and nonylphenol as effective components of Lix984N degraded almost completely after long-term recycling. Lix984N degraded through such reactions as Beck.mann rearrange, hydrolysis and sulphofication. The degradation of Lix984N would deteriorate solvent extraction and disengagement performance, and result in a more stable interracial emulsion.展开更多
Lix984N is intimately related to the dynamic characteristics of phase disengagement in copper solvent extraction because of its interfacial activity. With increasing Lix984N content, the phase disengagement time is pr...Lix984N is intimately related to the dynamic characteristics of phase disengagement in copper solvent extraction because of its interfacial activity. With increasing Lix984N content, the phase disengagement time is prolonged and the mechanism dominating phase disengagement process transfers from sedimentation to coalescence. The rate of droplet coalescence is faster than that of droplet sedimentation in the dense dispersion band when the volume fraction of Lix984N is less than 3.0%. The former almost equaled to the latter at Lix984N content of 3.0% and finally becomes lower than the latter when the volume fraction of Lix984N is more than 3.0%. The relationship between the adhesion force of two equal droplets and physical properties of fluids is deduced, which explains that the change of physical properties of organic phase with Lix984N content can make droplet coalescence more difficult and phase disengagement slower.展开更多
基金Project(50321402) supported by the National Natural Science Foundation of China
文摘The solvent extraction of copper and zinc from the bioleaching solutions of low-grade sulfide ores with LIX984 and D2EHPA was investigated. The influences of extractant content, aqueous pH value, phase ratio and (equilibration) time on metals extraction were studied. The results show that LIX984 has a higher selectivity for copper than for iron, zinc and other metals, and has the copper extraction rate above 97%, while the zinc and iron extraction rate is less than 1.6% respectively. Zinc extraction is carried out following the copper extraction from the raffinate. The zinc extraction with di(2-ethylhexyl) phosphoric acid(D2EHPA) is low due to its poor cation exchange. A sodium salt of D2EHPA is used and the zinc extraction rate is enhanced to above 98%. Though iron (Ⅲ) is strongly extracted before the extraction of zinc by D2EHPA, it is difficult to strip iron from the organic phase by sulfuric acid. The zinc stripping rate is above 99% with 100g/L sulfuric acid, while that of iron is 0.16%. Hence, the separation of zinc from iron can be achieved by the selective stripping.
基金Project (P1502) supported by Shanghai Leading Academic Discipline
文摘The organic phase separated from the interfacial crud provided by Dexing copper mine in Jiangxi, China, was analyzed by combined gas chromatography-mass spectroscopy. The results show that many kinds of emphiphiles containing such hydrophilic groups as carbonyl, carboxyl, sulphonyl or acylamine exist in organic phase. Conclusively, Lix984N would degrade gradually during a long-term contact with the acidic aqueous feed and strip reagents. Lix84 and nonylphenol as effective components of Lix984N degraded almost completely after long-term recycling. Lix984N degraded through such reactions as Beck.mann rearrange, hydrolysis and sulphofication. The degradation of Lix984N would deteriorate solvent extraction and disengagement performance, and result in a more stable interracial emulsion.
文摘Lix984N is intimately related to the dynamic characteristics of phase disengagement in copper solvent extraction because of its interfacial activity. With increasing Lix984N content, the phase disengagement time is prolonged and the mechanism dominating phase disengagement process transfers from sedimentation to coalescence. The rate of droplet coalescence is faster than that of droplet sedimentation in the dense dispersion band when the volume fraction of Lix984N is less than 3.0%. The former almost equaled to the latter at Lix984N content of 3.0% and finally becomes lower than the latter when the volume fraction of Lix984N is more than 3.0%. The relationship between the adhesion force of two equal droplets and physical properties of fluids is deduced, which explains that the change of physical properties of organic phase with Lix984N content can make droplet coalescence more difficult and phase disengagement slower.
