盐酸氧化酸浸亚硫酸钠浸出法处理银精矿氧化焙砂的研究

Treatment of Oxidizing Calcine of Ag Concentrate by Oxidizing Leaching with Hydrochloric Acid and Leaching with Sodium Sulfite

湿法炼锌过程中产出的铅银渣经硫化浮选得到的银精矿 ,通过氧化焙烧产出含银达± 1 .0 %的富银焙砂。研究了采用盐酸氧化酸浸预处理该富银焙砂以分离锌、铜等 ,同时使银转化为氯化银 ,再用亚硫酸钠碱性络合浸出转化渣回收银的工艺。考查了盐酸氧化酸浸过程中银的分散情况 ,结果表明 ,该过程中银的浸出率平均为 2 .7% ;采用了单因素条件试验研究方法 ,在试验的最佳条件下 ,富银焙砂经盐酸氧化酸浸后亚硫酸钠络合浸银 ,银的浸出率达 90 %以上 ,浸银液未经净化 ,直接用水合肼还原可得含量为 96 %以上的银粉。

The Ag-rich calcine with Ag ±1.0% was attained by oxidizing roasting of silver concentrate from sulphidizing flotation of Pb-Ag residue of zinc hydrometallurgy process. A method of recovery of Ag was studied. The method consists of two process as follows: firstly, the calcine with rich Ag was pre-treated by the process of oxidizing leaching with hydrochloric acid which aimed at not only separating Zn, Cu et al. but also turning Ag in the calcine into AgCl and entering into the converted residue; secondly, the converted residue was alkaline complexating leached with sodium sulfite. The dispersive proportion of Ag was examined in the process of oxidizing leaching of the calcine with hydrochloric acid, and it indicated that mean leaching rate of Ag is 2.7%. The researching method of condition experiment of single factor was introduced. At the optimal testing conditions, the leaching rate of Ag is above 90% in the process of complexating leaching with Na_2SO_3 after the calcine having been oxidizing leached with hydrochloric acid. The silver powder with above 96% Ag is gained by direct reducing with N_2H_2·H_2O from the solution of complexating leaching argent without purifying.