复杂钴白合金硫化焙烧酸浸过程中钴的提取行为

Extraction behavior of cobalt from complex cobalt white alloy by sulfidation roasting and acid leaching

本文针对钴白合金中钴难以实现高效节能回收的研究现状,以复杂钴白合金为研究对象、辉钼矿为焙烧硫化剂,通过钴白合金硫化焙烧-常压硫酸浸出工艺实现了钴的高效选择性提取。考察了焙烧温度、辉钼矿添加量和焙烧时间等对钴浸出的影响,并且通过XRD分析了焙烧及酸浸过程中的物相转变。结果表明:在焙烧温度1050℃、辉钼矿和钴白合金的质量比2∶1、焙烧时间90 min的条件下,钴白合金与辉钼矿反应转化为高浸出性能的三元硫化物(M_(x)Mo_(6)S_(8),M=Co,Fe,Cu;x=0~2),随后在常压硫酸浸出过程中,钴和铁被选择性浸出,浸出率均大于99%;而钼和铜不被浸出,以Cu_(0.5)Mo_(3)S_(4)和Mo_(3)S_(4)的形式富集于浸出渣中。此外,辉钼矿中的钼被转化为三元硫化物(M_(x)Mo_(6)S_(8)),钼的浸出性能也大大提高。

In view of the current research status that it is difficult to recover cobalt from complex Co-white alloy with energy conservation and high efficiency,cobalt white alloy was taken as research object,and molybdenite was used as sulfidation roasting agent to achieve the selective extraction of cobalt by sulfidation roasting-atmospheric sulfuric acid leaching process.The effects of roasting temperature,molybdenite addition,roasting time and other factors on cobalt leaching were investigated,and the phase transformation during roasting and acid leaching was analyzed by XRD.The results show that cobalt white alloy is converted into ternary sulfide(M_(x)Mo_(6)S_(8))with high leaching performance under the conditions of roasting temperature 1050℃,mass ratio of molybdenite to Co-white alloy 2∶1 and time 90 min.And then,cobalt and iron are selectively leached from the ternary sulfide with the leaching efficiency of all above 99%in atmospheric sulfuric acid leaching process,while the molybdenum and copper are existed in the form of Cu_(0.5)Mo_(3)S_(4) and Mo_(3)S_(4) in leaching residues.In addition,the leaching performance of molybdenum is also greatly improved due to its conversion into ternary sulfide(M_(x)Mo_(6)S_(8)).