Optimization of efficient stable reagent of alkaline thiourea solution for gold leaching

来源期刊：中南大学学报(英文版)2003年第4期

论文作者：王云燕 柴立元 闵小波 何德文 彭兵

文章页码：292 - 296

Key words：alkaline thiourea; gold leaching; stable reagent; Na₂SiO₃; Na₂SO₃; Na₂SeO₃

Abstract: Na₂SiO₃ and Na₂SeO₃ were chosen as stable reagents of alkaline thiourea solution substituting Na₂SiO₃, according to the structure-property relationship between the stability of alkaline thiourea and the structure of thiourea and sulfite ion, and the effect of the stable reagents on stability of alkaline thiourea was investigated. The results show that contrary to Na₂SeO₃, Na₂SO₃ and Na₂SiO₃affect the stability of alkaline thiourea solution remarkably. The stable effect of Na₂SiO₃on alkaline thiourea is obviously better than that of Na₂SO₃. The stable reagents Na₂SO₃ and Na₂SiO₃decrease the decomposition rate of alkaline thiourea solution greatly, and the decomposition rate of alkaline thiourea reduces from 72.5% to 33.8% with addition of 0.3 mol·L^-1 Na₂SiO₃. Dissolution currents of gold in the alkaline thiourea solution containing Na₂SO₃ and Na₂SiO₃ are 2.0 mA·cm^-2and 3.5 mA·cm^-2at the potential of 0.42 V, respectively, and Na₂SO₃ is consumed excessively due to the oxidation reaction of Na₂SO₃ occurring in the studied potential range. Na₂SiO₃ is an efficient stable reagent of alkaline thiourea solution, and gold dissolution is accelerated much more obviously by Na₂SiO₃ than by Na₂SO₃.

基金信息：the National Natural Science Foundation of China