铜镍合金选择性两段加压浸出试验研究

Experimental study on selective two-stage pressure leaching of copper nickel alloy

现有火法工艺处理铜镍合金时,存在物料反复冶炼、周转量大、贵金属分散、回收率低的问题,湿法工艺存在全浸液铜、镍分离难度大的问题。本文在分析铜镍合金成分的基础上,以镍冶炼厂产出的铜镍合金为原料开展试验研究,一段工序采用CuSO_(4)作为浸出剂,将镍单质和硫化镍转变为镍离子进入溶液,而铜离子形成沉淀进入渣相,实现镍的选择性浸出;二段工序在浸出渣中加入硫酸并通入氧气,将单质铜和硫化铜全部浸出,贵金属富集于渣中;三段工序对硫酸铜溶液进行浓缩结晶。结果表明,控制合适的两段加压浸出条件,产出总渣率为4.61%,铜的总浸出率为99.19%,镍的总浸出率为99.43%,贵金属富集倍数为21.69。浸铜液经浓缩结晶,产出硫酸铜结晶纯度为98.35%,符合硫酸铜结晶产品一级品标准要求。该工艺试剂用量少、无废水排放,是一种绿色环保工艺,具有推广价值。

At present,when dealing with copper-nickel alloy,the pyrometallurgical process has the problems of repeated smelting of materials,large turnover,dispersion of precious metals and low recovery rate;The hydrometallurgy process has the problem of difficult separation of copper and nickel in the full immersion solution.Based on the analysis of the composition of copper-nickel alloy,this paper carries out experimental research on copper-nickel alloy produced by the nickel smelter.In the first stage,CuSO_(4) was used as the leaching agent to convert nickel and nickel sulfide into nickel ions into solution,while copper ions form precipitates and enter the residue.In the second stage,sulfuric acid was added to the leaching residue and oxygen was introduced to leach copper and copper sulfide,and precious metals were enriched in the residue.The three-stage process concentrates and crystallizes the copper sulfate solution.The results show that the total residue yield is 4.61%,the total leaching rate of copper is 99.19%,the total leaching rate of nickel is 99.43%,and the enrichment multiple of precious metals is 21.69.The copper leaching solution was concentrated and crystallized,and the purity of copper sulfate crystal was 98.35%,which met the first-class standard requirements of copper sulfate crystal products.The process has less reagent consumption and no wastewater discharge.It is a green metallurgy process and has promotion value.