四川里伍铜矿尾矿生物浸出液中回收铜、锌的研究

Recovering Copper and Zinc from Bioleaching Lixivium of Liwu Copper Mine Tailings by Process of Solvent Extraction-Precipitation

为回收里伍铜矿尾矿生物浸出液中铜和锌,采用"萃取-沉淀"工艺流程,以CuSO_4/ZnSO_4水溶液-Lix984N/煤油-H_2SO_4体系为对象,考察料液pH值、萃取时间、相比等参数对铜萃取的影响及萃余液中锌的沉淀回收等。结果表明,当料液pH值为2.3、转速180r/min、萃取时间为4min、Lix984N体积分数为4%、相比(有机相和水相的体积比,O/A)为1.0时,铜萃取率为98.65%,锌萃取率为12.28%,铁萃取率为8.93%;当反萃取时间为2min、相比为1.0、硫酸质量浓度为100g/L时,铜离子的反萃取率为94.51%。Na_2CO_3用量与Na_2CO_3理论用量比为1.5g/g时,萃余液中锌沉淀率为99.32%。沉淀渣中锌、铁质量分数分别为39.56%和0.86%。"萃取-沉淀"工艺能有效回收里伍铜矿尾矿生物浸出液中的铜和锌。

The technological process of ＂extraction and precipitation＂was exploited for recovering copper and zinc in the bioleaching solution of Liwu copper mine. The system of CuSO_4-Zn SO_4 aqueous solution-Lix984N/kerosene-H_2SO_4 was applied to investigate the influence of pH value,extraction time,O/A,and so on,on copper extraction. The precipitation method was used to recover Zinc in raffinate. The results showed that the extraction rates of copper,zinc and iron were 98. 65%,12. 28% and 8. 93% respectively. When the pH value was 2. 3,the rotate speed was 180 r/min,the extraction time was 4 min,Lix984 N concentration was 4%,O/A was 1. 0. The reextraction rate of copper at 2 min of reextraction time,1. 0 of O/A,and 100 g/L of H_2SO_4 concentration,was 94. 51%. The precipitation rate of zinc in the raffinate at 1. 5（g/g） of Na_2CO_3 dosage/Na_2CO_3 theory dosage was 99. 32%. The mass fractions of zinc and iron in precipitation were 39. 56% and0. 86% respectively. The copper and zinc in the bioleaching solution of Liwu copper mine were recovered effectively by the ＂extraction and precipitation＂technological process.