氰化尾渣矿浆电解过程中黄铁矿的溶出研究

Study on pyrite dissolution during cyanide tailings slurry electrolysis

采用矿浆氯化电解技术无害化处理氰化尾渣,重点研究了电解过程中黄铁矿溶出的影响因素及反应机理。研究表明:在矿浆浓度10 g/L,电流密度800 A/m^(2),NaCl用量50 g/L,电解时间2.0 h的条件下,氰化尾渣中Fe平均浸出率达89.05%,平均质量损失率为38.96%。处理后尾渣中金品位由1.19 g/t提高到1.96 g/t,这对氰化尾渣的资源化、减量化及增值化利用具有重要的意义。矿浆电解过程中,黄铁矿在阳极被氧化成Fe^(3+)和SO_(4)^(2-),在阴极被还原成磁黄铁矿;Cl^(-)在阳极被氧化生成Cl_(2),Cl_(2)溶于水生成HClO和ClO^(-),黄铁矿和磁黄铁矿被HClO、ClO^(-)氧化,以Fe^(3+)和HSO_(4)^(2-)的形式进入到溶液中。

The cyanide tailings were treated with slurry chlorination electrolysis technology,and the influencing factors and reaction mechanism of pyrite dissolution during the electrolysis process are mainly studied.Results indicated that the average leaching rate of Fe in the cyanide tailings reaches 89.05%,and the mass loss rate is 38.96%when the pulp concentration was 10 g/L,the current density was 800 A/m^(2),the NaCl dosage was 50 g/L,and the reaction time was 2.0 h.The gold grade of the tailings after treatment is increased from 1.19 g/t to 1.96 g/t,which is of great importance for resource utilization,reduction,and value-added utilization of cyanide tailings.In the process of slurry electrolysis,pyrite is oxidized to Fe^(3+)and SO_(4)^(2-)at the anode,and reduced to pyrrhotite at the cathode.Cl^(-)is oxidized at the anode to generate Cl_(2),and Cl_(2)dissolves in the solution to generate HClO and ClO^(-).Pyrite and pyrrhotite are oxidized by HClO,ClO-and enter into solution in the form of Fe^(3+)and HSO_(4)^(2-).