Separation of Copper and Nickel by Solvent Extraction Using LIX 664N

Separation of copper and nickel by liquid-liquid extraction from aqueous solutions was studied using LIX 664N in kerosene as solvent. Both metals were taken in their sulfate form and ratio of copper to nickel in feed solutions was maintained as 10:1. LIX 664N concentration in kerosene was varied from 10% to 40% (v/v) and its effect was studied on percent extraction of copper and nickel for organic to aqueous (O:A) phase ratio of 2:1 at pH 2. Experimental results showed that at pH 2, copper was selectively extracted from its mixture with nickel. Selectivity for copper extraction was as high as 6000 with 40% LIX 664N. Calculations using extraction isotherm indicate almost complete recovery of copper in two stages with O:A ratio of 1:1 and in one stage with O:A ratio of 2:1. After extraction of copper, the pH of raffinate containing nickel was adjusted to a value of 9 by addition of ammonia solution. The effect of LIX 664N concentration on extraction of nickel was studied. Up to 80% nickel could be extracted with 30% LIX 664N at O:A phase ratio of 2:1. Stripping of copper from the organic phase with 180 g/l sulfuric acid at O:A phase ratio of 1:1 gave 98.5% copper recovery in a two-stage operation.

Solvent extraction of copper and zinc from bioleaching solutions with LIX984 and D2EHPA

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.

Extraction and stripping of Cu and Ni from synthetic and industrial solutions of Sarcheshmeh Copper Mine containing Cu, Ni, Fe and Zn ions

The extraction and stripping of Cu and Ni ions from synthetic and industrial solutions of Sarcheshmeh Copper Mine containing Cu(770 mg/L),Ni(3200 mg/L),Fe(800 mg/L)and Zn(200 mg/L)were comprehensively investigated using D2 EHPA,LIX 984,Cyanex 302,Chemorex CP 150 and Acorga 5774 diluted in kerosene.The influential parameters such as mixing speed and time,concentration of extractant,p H and temperature were considered in extraction stage.Furthermore,stripping of Cu and Ni was examined using different inorganic and organic acids(sulfuric,hydrochloric,nitric and citric acids)with different concentrations.The results indicated that the highest extractions of Cu and Ni occurred within 3 min,with the mixing speed of 500 r/min,28℃and A/O ratio of 1:1.Moreover,Cu was extracted by LIX 984 at the concentration of 10%(v/v),whereas Ni was extracted by Cyanex 302 at the concentration of 30%(v/v),efficiently.The optimal p H for Cu and Ni extraction is in ranges of 2-3 and 4-5,respectively.Cu and Ni were selectively extracted with the recoveries of 85%,93%and 77%,82%from synthetic and industrial solutions containing Ni,Cu,Zn and Fe ions,respectively.The results of optimal condition showed that 96%of Ni and 93%of Cu were stripped from the synthetic and industrial solutions.Finally,four elements Zn,Fe,Cu and Ni were extracted in three stages with D2 EHPA,LIX 984 and Cyanex 302 extractants respectively with the least impurities.

LIX 984萃取分离铜、镍的试验研究

本文针对铜镍矿常压直接浸出液萃取除铁后的硝酸介质体系，探讨了用ＬＩＸ９８４分离铜和镍的萃取及反萃条件。ｐＨ＝４．０和１０．５时分步采用２０％ＬＩＸ９８４－煤油２段萃取铜和镍，１．８ｍｏｌ／ｄｍ￣３Ｈ＿２ＳＯ＿４３段反萃，多级富集，得到４０ｇ／ｄｍ￣３纯的富铜液和富镍液，铜、镍萃取回收率分别为９９．７％和９９．３％。

Degradation of Lix984N and its effect on interfacial emulsion

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.