利用矿浆电解技术处理氰化尾渣  

Treatment of cyanide tailings with slurry electrolysis technology

作　　者：董萍 宋永辉[1,2] 张红菊 陈瑶 兰新哲 DONG Ping;SONG Yonghui;ZHANG Hongju;CHEN Yao;LAN Xinzhe(School of Metallurgical Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;Shaanxi Gold and Resources Key Laboratory,Xi'an 710055,China;Shaanxi Zinc Industry Co.Ltd.,Shangluo 726007,China)

机构地区：[1]西安建筑科技大学冶金工程学院,西安710055 [2]陕西省黄金与资源重点实验室,西安710055 [3]陕西锌业有限公司,商洛726007

出　　处：《环境工程学报》2021年第5期1662-1669,共8页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金资助项目(51774227);陕西省自然科学基金重点基金资助项目(2018JZ5011);陕西省自然科学基金陕煤联合基金资助项目(2019JLM-44)。

摘　　要：氰化提金所产生的氰化尾渣会带来环境污染隐患,而氰化尾渣的无害化处理是黄金冶炼行业节能减排及可持续发展面临的关键问题。采用一步矿浆电解技术对氰化尾渣进行无害化处理,研究了电解氯氧化处理过程中NaCl添加量、外加电压、极板间距和电解时间等因素对电解氧化效果的影响,并采用高精度矿物解离分析系统对氰化尾渣进行了分析表征。研究结果表明,在NaCl添加量0.5 g、外加电压8 V、极板间距10 mm、电解时间4 h的条件下,氰化尾渣CNT、 CN-、 Cu、 Fe及Zn离子的去除率分别为94.83%、 98.94%、 85.65%、84.51%与73.85%。随着NaCl添加量的增大,氰化尾渣中黄铁矿、磁黄铁矿与黄铜矿、闪锌矿等包裹矿物的解离度增大,黄铁矿与黄铜矿、闪锌矿的连生比例分别降低了12.04%、20.17%,黄铁矿的自由面积百分比降低了9.40%。电场作用下定向迁移至阳极的Cl-优先氧化生成Cl2/ClO-,与定向迁移至阳极附近的游离氰与金属氰络合离子发生氧化还原反应,使得氰化物被氧化为N2和CO2,部分金属离子则会在阴极发生电沉积反应,从而实现快速、高效无害化处理氰化尾渣的目标。In this paper, one-step pulp electrolysis technology is used to detoxify cyanide tailings from gold smelting. NaCl addition amount, applied voltage, electrode spacing and electrolysis time were studied on electrolytic oxidation during direct electrolytic chlorine oxidation. Mineral Liberation Analyzer was used to deeply analyze the oxidation reaction mechanism of cyanide and the main encapsulated minerals during the process. The results show that with NaCl dosage of 0.5 g, the applied voltage of 8.0 V, plate spacing of 10 mm and electrolysis time of 4 h, the removal rates of CNT, CN-, Cu, Fe and Zn in the slurry are 94.83%, 98.94%,85.65%, 84.51% and 73.85%, respectively. After the treatment, the proportion of pyrite from chalcopyrite and sphalerite continuously reduced by 12.04% and 20.17%, respectively, and free surface percentage content of pyrite reduced by 9.4%. Under the action of an electric field, Cl-migrates to the anode and preferentially oxidizes to Cl2/ClO-, which undergoes a redox reaction with the free cyanide and metal cyanide complex ions that migrate to the vicinity of the anode, resulting in the oxidation of cyanide to N2 and CO2, and some metal ions were precipitated by the electrodeposition reaction at the cathode. This study can achieve the goal of rapid,efficient and harmless treatment of cyanide tailings.

关 键 词：氰化尾渣 矿浆电解 氯氧化 阳极氧化 

分 类 号：T-F-09[一般工业技术] T-Q-536