缓释硫化剂ZnS去除冶炼污酸中As(Ⅲ)的试验及动力学研究  

Experimental and kinetic study on the removal of As(Ⅲ) from smelting waste acid by slow-release sulfiding agent ZnS

作　　者：张萌萌 李静[1,2,3] 董庆峰 ZHANG Mengmeng;LI Jing;DONG Qingfeng(Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China;National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology,Kunming 650093,China;Kunming Key Laboratory of Special Metallurgy,Kunming University of Science and Technology,Kunming 650093,China)

机构地区：[1]昆明理工大学冶金与能源工程学院,云南昆明650093 [2]微波能源与装备技术工程应用国家地方联合实验室,云南昆明650093 [3]昆明市特种冶金重点实验室,云南昆明650093

出　　处：《中国有色冶金》2025年第1期157-165,共9页China Nonferrous Metallurgy

基　　金：云南省科技厅重点研发计划(202403AA080004);云南省科技厅基础研究专项(202201AS070031);云南省科技厅重大科技专项计划(202302AG050008)。

摘　　要：冶炼污酸中含有大量砷,目前一般采用硫化-石灰中和铁盐法除砷,存在成本高、环境风险大、体系负担重等问题,问题出现的主要原因是硫化药剂在污酸中溶解度极高,难以与除砷速率形成完美匹配。本文提出了硫化锌缓释除砷技术,研究在E-pH分析的基础上进行了条件试验,并对ZnS除砷动力学进行研究,还根据反应产物的表征深度探究ZnS除砷机理,得到以下主要结论。在As-S-H_(2)O体系中,当pH值小于2时,砷离子处于As_(2)S_(3)稳定存在区域;ZnS缓释剂除砷的优化工艺条件为S/As物质的量比7.5、反应温度80℃、反应时间240 min,该条件下砷去除率达到98.42%,污酸砷含量由1 017 mg/L降低至16.04 mg/L;ZnS去除污酸中砷的反应速率受混合扩散模型控制,反应表观活化能为28.29 kJ/mol;ZnS为表面粗糙的球形颗粒,拥有较大比表面积,反应后污酸中的砷以As_(2)S_(3)沉淀的形式附着在ZnS表面。该工艺利用硫化锌溶解特性,在污酸中缓慢释放S^(2-)除砷,既避免了钠离子的引入,降低体系负担,同时减少环境风险,而且有效实现了污酸中砷的去除,为污酸处理提供了新思路。The smelting waste acid contains a large amount of arsenic.Currently,the conventional approach to arsenic removal involves the use of a sulfide-lime neutralization method for iron salts.However,this method is associated with high costs,environmental concerns,and a substantial burden on the system.The primary cause of these issues is the high solubility of the sulfide agent in the waste acid,which hinders its effectiveness in arsenic removal.This paper presents a slow-release arsenic removal technique using zinc sulfide(ZnS).The study is based on E-pH analysis of the test conditions,ZnS arsenic removal kinetics,and in-depth characterization of the reaction products to explore the ZnS arsenic removal mechanism.The main conclusions are as follows:In the As-S-H_(2O) system,when the pH value is less than 2,arsenic ions are found to be in the stable existence region of As_(2)S_(3).The most effective process conditions for arsenic removal by ZnS retardant are determined to be a S/As substance amount ratio of 7.5,a reaction temperature of 80 ℃,and a reaction time of 240 minutes.Under these conditions,the arsenic removal rate reaches 98.42%,and the arsenic content in the waste acid is reduced from 1 017 mg/L to 16.04 mg/L.The reaction rate of ZnS in removing arsenic from waste acid follows a mixed diffusion model,with an apparent activation energy of 28.29 kJ/mol.ZnS is a spherical particle with a rough surface and a large specific surface area,and arsenic in the waste acid adheres to the surface of ZnS in the form of As_(2)S_(3) precipitation after the reaction.This process takes advantage of the dissolution characteristics of zinc sulfide,slowly releasing S^(2-) to remove arsenic from the waste acid.It avoids the introduction of sodium ions,reduces the burden on the system,and lowers environmental risks,effectively removing arsenic from the waste acid.This provides a new approach for the treatment of waste acid.

关 键 词：冶炼污酸 缓释除砷 硫化锌 As_(2)S_(3)沉淀 E-pH分析 混合扩散模型 

分 类 号：TF813[冶金工程—有色金属冶金] X758[环境科学与工程—环境工程]