(中南大學(xué) 冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083)
摘 要: 進(jìn)行鐵礬渣熱硫酸分解和分解渣硫脲法提銀的試驗(yàn)研究，考察硫酸用量、分解溫度、反應(yīng)時(shí)間、液固比對(duì)鐵礬渣中Fe、Zn、Ag浸出率的影響，以及硫脲法提銀的最優(yōu)條件。結(jié)果表明：在硫酸用量為其理論值的1.5倍、分解溫度95 ℃、時(shí)間2.5 h、液固比2.5:1的最佳條件下，鐵礬渣中Fe和Zn浸出率分別為93.85%和92.25%，而Ag的浸出率僅為1.99%。分解液凈化后可用中溫水熱法制備鐵紅，分解渣中Ag富集到1060 g/t。在液固比10:1、硫脲濃度15 g/L、浸出溫度90 ℃、反應(yīng)時(shí)間2.5 h的最優(yōu)條件下，Ag的平均浸出率在93%以上，同時(shí)，渣中Pb的品位由1.7%提高到7.5%。
關(guān)鍵字: 鐵礬渣；濕法煉鋅；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
