用水合肼还原法从化学镀镍废液中回收镍

Researches on the Recycling of Nickel from Spent Electroless Nickel Plating Baths by Hydrazine Reduction

化学镀镍废液量大,且含有镍和磷等资源,废液处理关系到资源循环利用与环境保护的问题。研究了以水合肼为还原剂回收化学镀镍废液中镍的工艺。实验结果表明,在初始化学镀镍废液中pH=6.5、水合肼质量浓度为20mL/L、θ为85℃,反应t为1.5h,废液的镍回收率可达98.5%～98.9%,残液中ρ(Ni2+)为71.7～94.1mg/L,析出的产物为黑色微粒,w(镍)为90.5%～91.5%,w(磷)为7.9%～8.5%。

Considering the serious environmental problem and recent high nickel prices, it is urgent to develop an effective nickel recycling technique to treat a large amount of the spent electroless nickel plating baths. In this research, the recycling techniques of nickel from spent electroless nickel plating baths using hydrazine as the reductant were studied. The experimental results showed that a high nickel （Ⅱ） recovery rate of 98.5%～98.9% could be obtained after treating for 1.5 h at 85 ℃ with an initial pH of 6.5 in the presence of 2.0 mL/L hydrazine spent baths. The mass concentration of nickel （Ⅱ） in the treated solution was 71.7～94.1 mg/L, and the recovered products were black particles containing elements of 90.5%～91.5% nickel and 7.9%～8.5% phosphorus.