(中南大学 冶金与环境学院，长沙 410083)
摘 要: 进行铁矾渣热硫酸分解和分解渣硫脲法提银的试验研究，考察硫酸用量、分解温度、反应时间、液固比对铁矾渣中Fe、Zn、Ag浸出率的影响，以及硫脲法提银的最优条件。结果表明：在硫酸用量为其理论值的1.5倍、分解温度95 ℃、时间2.5 h、液固比2.5:1的最佳条件下，铁矾渣中Fe和Zn浸出率分别为93.85%和92.25%，而Ag的浸出率仅为1.99%。分解液净化后可用中温水热法制备铁红，分解渣中Ag富集到1060 g/t。在液固比10:1、硫脲浓度15 g/L、浸出温度90 ℃、反应时间2.5 h的最优条件下，Ag的平均浸出率在93%以上，同时，渣中Pb的品位由1.7%提高到7.5%。
关键字: 铁矾渣；湿法炼锌；Ag；硫脲；分解
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:The decomposition of sodium jarosite in H2SO4 medium and recovery of silver from silver bearing decomposition residue were studied. The effects of H2SO4 additions, decomposition temperature, time and liquid-solid ratio on leaching rate of Fe, Zn and Ag were investigated. The results show that, under the following optimum conditions of H2SO4 additions 1.5 times of its experimental value, temperature of 95 ℃, reaction time of 2.5 h and liquid-solid ratio of 2.5？1, the leaching rates of Fe and Zn can reach 93.85% and 92.25%, the mean leaching rate of Ag is only 1.99%. After being purified, the decomposition solution is used to explore the preparation of iron oxide red by hydrothemal method and silver in decomposition residue can be enriched to 1060 g/t. And then, the optimal conditions of recovery of silver with thiourea solution is determined as follow: thiourea concentration of 15 g/L, liquid-solid ratio of 10:1, temperature of 90 ℃, time of 2.5 h. The results show that the leaching rate of Ag can reach 93%, and then, the lead contents are also improved from 1.7% to 7.5%.
Key words: jarosite residue; zinc hydrometallurgy; silver; thiourea; decomposition
