沉淀-电解氧化法处理高铁氰化废水  

Ferrocyanide wastewater treated by precipitation-electrolytic oxidation process

作　　者：赵玲玲 宋永辉[1,2] 曾鑫辉 李一凡 兰新哲 ZHAO Lingling;SONG Yonghui;ZENG Xinhui;LI Yifan;LAN Xinzhe(School of Metallurgical Engineering,Xi′an University of Architecture and Technology,Xi′an 710055,China;Key Laboratory of Gold and Resource of Shaanxi Province,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：《环境工程学报》2020年第12期3426-3434,共9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(2018JZ5011);陕西省自然科学基金企业联合项目(2019JLM-44)。

摘　　要：采用沉淀-电解氧化联合技术处理高铁氰化提金废水,重点考察了沉淀剂添加量、沉淀时间、温度、电解电压、电解时间等因素对总氰、游离氰和铁氰络合物去除率的影响。结果表明,随着CuCl2加入量的增大,氰化废水中各主要离子的沉淀率逐步增加。常温下向100 mL含氰废水中加入3.0 g CuCl2并搅拌40 min后,总氰(CNT)、CN^−、Fe离子的去除率分别可达到95.29%、98.00%与100%。以钛板为阴阳极,采用一阴两阳体系对沉淀后液进行电解氧化实验,当电压为6 V、极间距为15 mm、电解时间为5 h、初始浓度为60%的条件下,CNT和CN−的去除率最高可达到99.76%和99.90%。XRD分析表明,沉淀过程中铜氰、铁氰络合离子的去除主要归因于CuCN、Cu2Fe(CN)6、CuSCN等沉淀的形成。电解氧化过程中随着外加电压与氯离子浓度的增大,废水中残存的游离氰与金属氰络合离子的去除率逐渐增加,这主要是阳极反应产生的Cl2/ClO−等强氧化剂作用的结果。以上研究结果可为高铁氰化提金废水的综合处理提供参考。The precipitation-electrolytic oxidation combined technology was used to treat high-ferric cyanide gold-lifting wastewater,and the effects of factors such as the dosage of precipitant,precipitation time,temperature,electrolysis voltage,and electrolytic time on the removal rates of total cyanide,free cyanide,and ferric cyanide complex were investigated.The results showed that with the increase of the dosage of CuCl2,the precipitation rate of the main ions in the cyanide wastewater increased gradually.At the CuCl2 dosage of 3.0 g to 100 mL of cyanide-containing wastewater,40 min-stirring and room temperature,the removal rates of CNT,CN^−,and Fe ions could reach 95.29%,98.00%and 100%,respectively.The titanium plate was used as the cathode and anode,and the electrode parallel system(one cathode and two anodes)was used to conduct electrolytic oxidation experiments on the precipitated solution.When the voltage was 6 V,the electrode spacing was 15 mm,electrolysis time was 5 hours and the initial concentration was 60%,the removal rates of CNT and CN−could reach 99.76%and 99.90%,respectively.XRD analysis showed that the removal of copper cyanide and iron cyanide complex ions during precipitation was mainly attributed to the formation of CuCN,Cu2Fe(CN)6,CuSCN and other precipitates.With the increase of the applied voltage and chloride ion concentration during electrolytic oxidation,the removal rates of residual free cyanide and metal cyanide complex ions in wastewater increased gradually,which was mainly due to the strong oxidation of Cl2/ClO−produced during the anode reaction.The research results can provide a reference for the treatment of high-ferric cyanide gold-lifting wastewater.

关 键 词：氰化物 铁氰络合物 化学沉淀 电解氧化 

分 类 号：X703[环境科学与工程—环境工程]