提高福美钴渣中金属浸出率试验研究

Experimental study on improving the leaching rate of metal in Fume sodium cobalt residue

湿法炼锌净化除钴工艺生成的福美钴渣含有可回收的锌、钴等金属,但湿法工艺条件下福美钴渣非常难处理,目前鲜有福美钴渣回收工艺的文献。本文设计氧化焙烧-酸性浸出工艺试验回收福美钴渣中有价金属,系统性地对影响锌、钴浸出率的影响因素进行了研究分析,得出了最佳工艺条件和试验结果。在氧化焙烧温度900℃、空气过剩系数1.6、焙烧时间2 h的条件下,金属锌和钴的回收率分别为99.62%和99.08%,脱硫率69.41%。第一段弱酸浸出,每公斤焙烧矿加入硫酸(93%) 0.4 L,液固比2.5,自然反应温度,浸出时间1 h;第二段为高酸浸出工艺,每公斤焙烧矿加入硫酸(93%) 0.3~0.45L,温度60℃,液固比4,浸出时间2 h。经过两段逆流浸出后,焙烧矿中主要有价金属锌、钴浸出率分别达到98.77%和97.98%,镉、铜和铁的浸出率分别为96.19%、99.37%和41.13%。

The Fume sodium cobalt residue produced by the purification cobalt removal process of zinc hydrometallurgy contains recoverable zinc,cobalt and other metals.However,the Fume sodium cobalt residue is very difficult to deal with under the conditions of the wet process.At present,there are few documents on the recycling process of Fume sodium cobalt residue.In this paper,an oxidation baking-acid leaching process experiment was designed to recover valuable metals from the Fume sodium cobalt residue,and the factors affecting the leaching rate of zinc and cobalt were systematically studied and analyzed,and the best process conditions and test results were obtained.Under the condition of oxidation baking temperature 900℃,air excess coefficient 1.6,roasting time 2 h,the recovery rates of zinc and cobalt are 99.62%and 99.08%,and the desulfurization rate is 69.41%.In the first stage of weak acid leaching,0.4 L sulfuric acid(93%)is added into per kilogram of roasted ore,the liquid-to-solid ratio is 2.5,the reaction temperature is natural,and the leaching time is 1 h;the second stage is a high-acid leaching process,in which 0.3-0.45 L sulfuric acid(93%)is added into per kilogram of roasted ore,the temperature is 60℃,the liquid-solid ratio is 4,and the leaching time is 2 h.After two stages of countercurrent leaching,the leaching rates of the main valuable metals zinc and cobalt in the roasted ore reached 98.77%and 97.98%,respectively,and the leaching rates of cadmium,copper and iron were 96.19%,99.37%and 41.13%,respectively.