电渗析法回收铅酸蓄电池化成工序废硫酸的研究  

Sulfuric Acid Recovery from the Waste Acid Generated in Formation-Process of a Lead-Acid Battery Plant by Electrodialysis

作　　者：王娟[1] 林晗[1] 汪群慧[1] 马宁[2] 程桂石[1] 张健[1] 

机构地区：[1]北京科技大学土木与环境工程学院,北京100083 [2]中元国际工程设计研究院,北京100084

出　　处：《高校化学工程学报》2014年第6期1384-1390,共7页Journal of Chemical Engineering of Chinese Universities

基　　金：环保公益性行业科研专项(20130923)

摘　　要：本研究采用单价阳离子交换膜电渗析法,对北方某铅酸蓄电池厂化成车间产生的含低浓度铁离子的废酸进行回收实验。比较了单价阳离子交换膜和普通阳离子交换膜的分离性能,并且考察了操作电流密度、初始铁离子浓度以及初始硫酸浓度对硫酸回收率的影响。结果表明,当硫酸回收率达到80%时,单价阳离子交换膜对金属离子和氢离子的分离系数约为普通阳离子交换膜的7.5倍。在电流密度0.06 A·cm-2的条件下,采用单价阳离子膜对工厂化成废酸(初始硫酸浓度约2.25 mol·L-1,初始铁离子浓度约12 mg·L-1)电渗析,当废酸回收率达到80%时,金属铁离子的透过率小于10%,可控制回收酸中铁离子的浓度在2 mg·L-1以下,满足该蓄电池厂对化成硫酸中铁离子浓度的限值要求。通过对H+传质过程进行动力学分析的结果表明:其传质过程符合零级反应动力学,电迁移传质在传质过程中占主要地位。回收得到的硫酸重新回用于蓄电池的化成工序,不仅能够实现资源的回用,还可避免废酸进行中和处理时对碱的消耗,具有较好的环境效益及技术可行性。Electrodialysis method using monovalent cation-selective membranes （MCSM） was used to recover sulfuric acid from the formation-process waste acid which is generated in a lead-acid battery plant in northern China and contains a low concentration of iron ions. The separation capabilities of MCSM and SCEM （standard cation exchange membranes） were compared, and the effects of operation current density, initial iron ions concentration, and initial sulfuric acid concentration on the recovery efficiency of sulfuric acid were also investigated. The results indicate that when the recovery efficiency of sulfuric acid is 80%, the separation coefficient of MCSM for hydrogen and iron ions is as approximately 7.5 times as that of SCEM. In this research, the formation-process waste acid （initial sulfuric acid and iron ions concentrations are 2,25 mol.L-1 and 12 mg.L-1, respectively） was treated by electrodialysis using MCSM. When the current density is set at 0.06 A.cm-2, the sulfuric acid recovery efficiency is 80%. The permeation ratio of iron ions is less than 10%, and consequently the iron ions concentration of the recovered sulfuric acid is under 2 mg.L-1, satisfying the requirement of iron ions concentration limitation in formation acid for battery production. Moreover, the kinetics of H mass transfer was analyzed. The results suggest that the process is consistent with zero-order reaction kinetics and electromigration dominates the mass transfer process. Based on our results, theelectrodialysis with MCSM is an effective method for waste sulfuric acid recovery. Reutilization of the recovered sulfuric acid in the formation-process can help to reduce the amount of resources needed and avoid alkali consumption used for neutralizing the waste acid, thus achieving considerable environmental benefits and alleviating the resource pressure by the ever-increasing requirements of human beings.

关 键 词：电渗析 单价阳离子交换膜 酸回收 电池化成废水 

分 类 号：X784[环境科学与工程—环境工程]