全湿法回收银铋渣中有价金属的试验研究

针对火法和氯化法处理银铋渣的弊端，提出了全湿法处理银铋渣的新工艺。按照试验所确定的最佳条件，用稀硫酸浸锌、用硝酸浸其它金属，结合食盐沉银、中和水解沉铋、含铜ZnS04溶液的锌粉置换除杂和蒸发结晶等从浸出液中提取金属的手段，有效实现了Au、Ag、Bi、Zn、Cu等有价金属的分离回收，可获得金渣、银粉、次硝酸铋、工业硫酸锌和海绵铜产品，Au、Ag、Bi、zn、cu的直收率分别达到99．64％、98．23％、97．76％、96．37％和95．83％。全湿法新工艺工艺简单，加工成本低廉，适于中小型工业化生产。

Experiment Research of Recovering Valuable Metals from Silver-bismuth Slag by Whole-wet Method

In view of the malpractice in treating Ag-Bi slag by fire method and chlorinating method, a new technology of whole-wet method for Ag-Bi slag treatment was proposed. In accordance with the test-determined optimum conditions, means of extracting metals from the leachate were used, such as zinc leaching with dilute sulfuric acid and other metals leaching with nitric acid, silve settlement by table salt, bismuth settlement by neutralization and hydrolysis, zinc powder replacement for purification of copper containing ZnSO 4 solution and crystaliztaion by evaporation. The separation and recovery of valuable metals such as Au,Ag,Bi,Zn and Cu were effectively realized, obtaining products of gold residue, silver powder, bismuth hyponitrite, industrial grade zinc sulphate and sponge copper with the direct recovery of Au, Ag, Bi, Zn and Cu being up to 99.64%,98.23%,97.76%,96.37% and 95.83% respectively. The new whole-wet method is simple in technology and low in operation cost and, therefore, suitable for use in industralized production of small-and medium-scale.