矿山含铜酸性废水硫化沉淀过程中硫化氢产生量的控制

Control of hydrogen sulfide production in sulfide precipitation of mine acid copper-containing wastewater

对矿山含铜酸性废水硫化沉淀的过程进行了理论分析和实验研究,并提出了控制硫化氢气体产生量的措施。实验结果表明:在矿山含铜酸性废水硫化沉铜过程中,硫氢化钠被Fe^3+还原成单质硫的反应最容易发生,其次为硫氢化钠与Cu^2+生成CuS沉淀的反应,产生硫化氢气体的趋势很弱,而生成FeS的趋势最弱;当反应终点电位控制在200 mV时,铜基本上沉淀完全,铁沉淀率很小;硫氢化钠的过剩量较小,可在最大程度上减少硫化氢气体的产生量;随着溶液酸度增加,硫化氢气体的产生量逐渐增加。硫化沉淀反应体系的硫酸质量浓度宜控制在小于4 g/L。

The process of sulfide precipitation of mine acid copper-containing wastewater was theoretical analyzed and experimental studied,and the measures for control of hydrogen sulfide production were put forward.The experiment results show that:In the sulfide precipitation process,the reaction of reducing sodium hydrosulfide by Fe3+to elemental sulfur is most likely to occur,followed by the reaction of sodium hydrosulfide and Cu2+to generate CuS,and the tendency to produce hydrogen sulfide gas is very weak,while the trend of generating FeS is weakest;When the endpoint potentialis controlled at 200 mV,copper is almostprecipitatedcompletely,and the precipitation rate of iron is very small;In this case,there is very little excess of sodium hydrosulfide which canminimize the generation of hydrogen sulfide gas;With the increase of sulfuric acid concentration,the productionamount of hydrogen sulfide gasgradually increases.The mass concentration of sulfuric acid in the sulfide precipitation reaction system should be controlled below 4 g/L.