通过循环伏安法测定了Pb及Pb-PbO2 电极在1.0mol/L H2SO4 介质中,Cr2(SO4)3 发生电化学氧化的相关参数,选择Pb-PbO2 电极为阳极,采用双室隔膜电解槽进行电化学氧化再生不锈钢着色老化液,确定了操作工艺条件如下:阴极支持液为5%的H2SO4 溶液,阳极电流密度为5A/dm2。恒电流电解7.5h,三价铬转化率为25.97%,电流效率为68.45%。经过电化学氧化法再生后,老化液中的Cr6+ 即恢复至效用范围,用于着色不锈钢片能达到与新配制的着色液一致的效果。

Electrochemical parameters of Cr2 (SO4)3 on Pb and Pb-PbO2 electrode in 1.0 mol/L H2SO4 were measured by cyclic voltammetry, respectively. Dual-chamber diaphragm cell, with Pb-PbO2 electrode as the anode, was used to electrochemical oxidation. The optimum conditions of electro-oxidation process were listed as following: 5% H2SO4 as cathode liquid, 5 A/dm2 anode current density, 7.5 h constant current electrolysis. The conversion of Cr3+ was 25.97%, and current efficiency was 68.45%. After being treated, the content of Cr6+ in ageing liquid was recovered to the effective range. The effect of colored stainless steels treated in the regenerated liquid was consistent with those treated in freshly prepared coloring liquid.