硫酸酸洗废液电解—萃取除Cr回收利用的研究

Study on Recovery and Utilization of Chromium Removal by Electrolysis-Extraction from Sulphuric Acid Pickling Waste Liquor

针对硫酸酸洗废液的排放而导致的金属资源浪费的问题,对其Cr的回收利用进行了研究。采用电解-萃取结合的方法,考察了Fe(Ⅱ)浓度、电流密度和电解时间对Cr(Ⅲ)转化率的影响,萃取剂三正辛胺(TOA)浓度和萃取时间对Cr(Ⅵ)萃取率的影响,得到最佳工艺条件。结果表明,制备的阳极板可成功用于电解;当电流密度为1000 A/m^2,电解时间为14 h、TOA浓度为Cr的三倍、萃取时间为60 s时,硫酸酸洗废液中Fe的损失率仅为22.24%,Cr回收率可到95%。采用电解--萃取法回收硫酸酸洗废液中Cr,不仅有益于资源节约,而且提供了一种高效、绿色废水处理的技术。

To solve metal resources waste phenomenon caused by sulphuric acid pickling oeffuent,chromium removal from which was studied.Byadopting electrolysis-extraction method,the optimal reaction conditions were obtained by studying effects of Fe(Ⅱ)concentration,current density andelectrolysis time on Cr(Ⅱ)conversion ratc,and impacts of TOA concentration and extraction time on Cr(Ⅵ)cextraction rate.Resuts show thttheprepared anode plate can be successfully applied in electrolysis,Fe loss rate from sulfuric acid pickling waste liquor is only 22.24%,and recovery rateof Cr is up to 95%under the condition of current density being 100 A/m^2,electrolysis time being 14 h,TOA concentration being three times as thatof Cr,and extraction time being 60 s.Hence,recovery of chromium fromsulphuric acid pickling efuent using electrolysis-extraction not only isbeneficial to resource conservation,but also provides a highly efficient green technology forwastewater treatment.