硫酸镍电解液净化除杂工艺研究

对硫酸镍电解液的萃取净化除杂进行了系统的研究。实验采用M5640对铜离子进行除杂,实验条件为:pH值为3.0,相比为1∶1,萃取剂体积浓度为15%,振荡时间5min,在此实验条件下铜离子的萃取率大于99.83%,其含量小于0.1mg·mL-1,已达到5N镍电解液标准。去除铜离子之后,采用P507对电解液进行除杂,在实验条件pH为4.0,相比为1∶1,萃取剂体积浓度为15%,振荡时间5min下,二价铁离子、锌离子、铅离子的萃取率分别为:99.93%,99.75%,84.01%,其含量分别为:0.10,0.21,0.30mg·mL-1,已达到5N镍电解液标准。在此之后再采用P507对电解液中钴离子进行去除,实验条件为:用氢氧化钠溶液均相制皂75%,提高待萃液当中钴离子的含量至4.19g.L-1,即Co/Ni为1/10。实验采取四级萃取,控制水相pH值在4～5之间。钴离子萃取率为74.92%,含量为14.88mg·mL-1,已达到5N镍电解液标准。

Purification of Nickel Sulphate Electrolyte

The extraction of nickel sulphate electrolyte was studied. M5640 was used to remove Cu~(2+). The extraction rate was higher than 99.83% and the content of Cu~(2+) was lower than 0.1 mg·L~(-1) according to the experiment conditions. And the conditions were as follows: pH was 3.0, O/A was 1: 1, the volume concentration of M5640 was 15%, and the reaction time was 2 min. After Cu~(2+) was removed, P507 was used to remove other impurities, such as Fe~(2+) , Zn~(2+), Pb~(2+). The contents of these impurities were removed lower than 0. 10, 0.21 and O. 30 mg·L~(-1) respectively. The conditions were as follows: pH was 4.0, O/A was 1: 1, and the reaction time was 5 rain. Then P507 was also used to remove Co~(2+). The conditions were as follows: firstly P507 was 75% saponifieated by sodium hydroxide solution. Secondly the content of Co~(2+) was increased to 4.19 g·L~(-1)( Co/Ni was 1/10). Thirdly pH was controlled between 4 and 5. After four times extraction the content of Co~(2+) was reduced to 14.88 mg·L~(-1), and the extraction rate of Co~(2+)was 74.92%. Its content was qualified to the standard of 5N nickel sulphate electrolyte.