扩散渗析法回收废铅膏电解液中硫酸的实验研究

Experimental study on recovery of sulfuric acid from waste lead paste electrolyte by diffusion dialysis

工业废旧铅蓄电池电解产生的酸性废水中含有大量硫酸,对其中的硫酸进行回收利用。以工业废铅膏为原料进行固相电解,产生硫酸浓度约20 g/L的废酸。采用7171阴离子交换膜,通过扩散渗析法对废铅膏电解液中的硫酸进行回收,两段酸回收率约75.2%。根据废铅膏电解液杂质含量情况,选择钠离子对硫酸的回收进行实验分析,结果表明酸的浓度不同,钠离子的浓度变化不同;钠离子扩散渗析是一个独立的过程,与溶液的酸浓度无关,只与自身的浓度差有关;硫酸的扩散渗析过程与溶液的硫酸浓度有关。扩散渗析模拟实验验证了扩散渗析能有效的回收硫酸。

The acid waste water that produced by electrolysis of industrial waste lead-acid batteries contains a large amount of sulfuric acid,which is recycled.Industrial waste lead paste was used as raw material for solid phase electrolysis to produce waste acid with sulfuric acid concentration of about 20 g/L.The sulphuric acid in waste lead paste electrolyte was recovered by diffusion dialysis with 7171 anion exchange membrane,and the recovery rate of two-stage acid was about 75.2%.According to the impurity content of waste lead paste electrolyte,sodium ion was selected to recycle sulfuric acid for experimental analysis.The results show that the concentration of sodium ion varies with the concentration of acid.Diffusion dialysis of sodium ions is an independent process,independent of the acid concentration of solution,only related to its own concentration difference;The diffusion dialysis process of sulfuric acid is related to the concentration of sulfuric acid in solution.The simulation experiment of diffusion dialysis verifies that the diffusion dialysis can effectively recover the sulfuric acid.