微电解-絮凝沉淀协同处理氰化提金废水的研究  

Study on synergistic treatment of cyanidation gold extraction wastewater by micro-electrolysis-flocculation precipitation

作　　者：周佳梦 宋永辉[1,2] 张盼盼 王一帆 廖龙 ZHOU Jiameng;SONG Yonghui;ZHANG Panpan;WANG Yifan;LIAO Long(School of Metallurgical Engineering,Xi’an University of Architectural Science and Technology,Xi’an 710055,China;Shaanxi key Laboratory of Gold and Resources,Xi’an 710055,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

出　　处：《化学工业与工程》2024年第3期98-105,共8页Chemical Industry and 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联合资助项目(2019JLM-44)。

摘　　要：采用微电解-絮凝沉淀技术处理高浓度氰化提金废水,主要研究了电压、电解时间、极板间距、温度、聚合氯化铁(PFC)添加量对CNT、CN-、Cu和Zn离子去除率的影响及过程反应机制。结果表明:室温条件下,以钛板为阴极、石墨板为阳极,采用一阴两阳电解体系处理氰化提金废水,当PFC添加量为750mg·L^(-1),电压4.5V,时间3h,极板间距10mm时,废水中CNT、CN-、Cu和Zn离子的去除率分别为97.29%、97.83%、99.36%和98.74%,处理后废水可直接返回浸出系统。电场作用下废水中原有的Cl-及PFC解离产生的Cl-定向迁移至阳极发生氧化反应,产生的Cl2及ClO-将阳极附近的游离氰、金属氰络合离子间接氧化生成N2和CO_(2),释放出的重金属离子部分在阴极电沉积析出,部分Cu^(2+)会以Cu(OH)2沉淀形式被去除,Zn^(2+)与Cu(CN)32-发生共沉淀以Zn(CN)2及CuCN沉淀形式被去除。同时,微电解-絮凝与PFC水解互相促进,水解产生的氢氧化物与多核羟基络合物通过吸附、絮凝作用有助于沉淀物的快速沉降。采用该技术可达到快速高效去除氰化物及综合利用有价金属的目的,为氰化提金废水的无害化处理与资源综合利用提供了新的途径。Microelectrolysis-flocculation and sedimentation technology was used to treat high-concentration cyanide gold extraction wastewater.The effects of voltage,electrolysis time,electrode spacing,temperature,and polymerization ferric chloride(PFC)addition on the removal rate of CNT,CN-,Cu,and Zn ions and its process reaction mechanism were mainly studied.The results show that at room temperature,with titanium plate as cathode and two graphite plates as anodes,this electrolysis system(one cathode and two anodes)was used to treat cyanide wastewater.The removal rates of CNT,CN-,Cu,and Zn ions in the wastewater can reach 97.29%,97.83%,99.36%and 98.74%respectively when the PFC dosage of 750 mg·L^(-1),the voltage of 4.5 V,the time of 3 h and the distance between the plates of 10 mm.And the treated wastewater can be directly returned to the leaching system.Under an electric field,the original Cl-in the wastewater and the Cl-generated by the dissociation of the PFC migrate directional-ly to the anode for oxidation reaction.The free cyanide and metal cyanide complex ions migrating near the anode are oxidized to N2 and CO_(2)indirectly by generated Cl2 and ClO-.Some of the heavy metal ions re-leased by the metal cyanide complex ions are electrodeposited at the cathode.Part of Cu^(2+)will be re-moved in the form of Cu(OH)2 precipitation,Zn^(2+)and Cu(CN)2-3 co-precipitate will be removed in the form of Zn(CN)2 and CuCN precipitation.Meanwhile,micro-electrolysis-flocculation and PFC hydrolysis promote each other.The hydroxides and polynuclear hydroxyl complexes produced by the hydrolysis con-tribute to the rapid sedimentation of the precipitate through adsorption and flocculation.The technology can achieve the purpose of rapid and efficient removal of cyanide and comprehensive utilization of valua-ble metals,providing a new way for the harmless treatment and comprehensive utilization of cyanidation gold extraction wastewater.

关 键 词：微电解-絮凝沉淀 聚合氯化铁 氰化提金废水 金属氰络合离子 

分 类 号：X703[环境科学与工程—环境工程]