漂浮阳极泥富集金银及回收锑铋工艺

Enrichment of Au and Ag and recovery of Sb and Bi from floating anode slime

采用盐酸浸出漂浮阳极泥富集金银,浸出液经过2次水解分别回收锑铋,考察反应温度、盐酸浓度、液固比和反应时间对盐酸浸出过程中锑铋浸出率的影响,稀释比对锑水解过程中锑水解率的影响以及终点pH对铋水解过程中铋水解率的影响。研究结果表明:当盐酸浓度为6 mol/L,固液比为1:5,反应温度为80℃,反应时间为1 h时,锑、铋浸出率分别可达到99.2%和99.1%;浸出后的漂浮阳极泥与浸出前相比,金、银富集15倍以上。用水按稀释比8:1稀释盐酸浸出液,进行锑的水解,锑水解率为95%,锑的总回收率为94.2%;用氢氧化钠调节锑水解液pH为8,进行铋的水解,铋的水解率为99.5%以上,铋总回收率为90%以上;铋水解液含杂质较低,返回锑的水解稀释盐酸浸出液,水可以循环利用。

Floating anode slime was leached by hydrochloric acid to enrich Au and Ag.The leaching solution was used to recover Sb and Bi by twice hydrolysis,respectively.Effects of reaction temperature,concentration of hydrochloric acid,reaction time on leaching rates of Sb and Bi during hydrochloric acid leaching process,effect of dilution ratio on hydrolysis rate of Sb during hydrolysis process of Sb and effect of final pH on hydrolysis rate of Bi during hydrolysis process of Bi were investigated.The experimental results show that the leaching rates of Sb and Bi are 99.2% and 99.1% when hydrochloric acid concentration is 6 mol/L,reaction temperature is 80℃,ratio of solid to liquid is 1：5,reaction time is 1 h.Compared with not-leached floating anode slime,the content of Au and Ag in leached floating anode slime are enriched by more than 15 times.The hydrolysis rate of Sb is 95% after the hydrochloric acid leaching solution is diluted 8 times by water to hydrolyze Sb,and the total recovery rate of Sb is 94.2%.The hydrolysis rate of Bi is 99.5% when the hydrolysate of solution is adjusted to pH=8 by NaOH after hydrolyzing Sb3＋,and the total recovery rate of Bi is more than 90%.For its low impurity content,the solution of hydrolyzing Bi3＋ is used to dilute hydrochloric acid leaching solution.