Method for producing high-purity nickel

Abstract

A method for producing high-purity nickel, which involves using a hydrochloric acid solution system to electro-deposit high-purity nickel, characterized in that, it includes the following steps sequentially: 3N-grade-grade electrolytic nickel was used as anode and the electro-deposition was carried out in a hydrochloric acid system, the solution obtained from the electro-deposition was extracted by a three-level countercurrent extraction using anion extraction solvents, and then back-extracted and degreased. After that, the solution was passed through the anion exchange resin to be further purified by ion exchange, and finally put into the electrolytic cell to deposit nickel. The amount of the solution that was put into the cell and the amount of the solution that was drawn out of the cell after the electro-deposition was the same? After the glow discharge analysis by a mass spectrography, the high-purity nickel obtained by the method according to the present invention was the 5N-grade-grade high-purity nickel. The cost was low and the contamination was prevented.

1 . Method for producing high purity nickel, characterized in that it involves the sequential steps:
 a. Employing 3N-grade electrolytic nickel as anode and corrosion resistant titanium wire as cathode, electrolyzing in hydrochloric acid system are electrolyse to prepare NiCl 2  solution at the current density of about 100 A/m 2  to 200 A/m 2 ; and at the end of electrolysis when the concentration of H +  is about 1 g/l to 2 g/l, electrolyzing at the current density of about 30 A/m 2  to 70 A/m 2  to a pH of the solution of about 1 to 3   b. After degreasing the back-extracted solution through the activated carbon column, then purifying the said solution through ion-exchange column of mixed anion exchange resin of anion exchange resin 331, 717, D301 and D401 at the exchange follow rate equal to or less than 2 BV/h. Main impurities of the prepared solution can be follows: Co and Fe less than 0.001 g/l each, and Cu, Pb and Zn less than 0.0002 g/l each; and   c. electro-depositing in solution purified by ion exchange resin in electrolytic cell at a pH of about 1 to 3, the current density of about 100 A/m 2  to 200 A/m 2  and a temperature of about 40° to 60°, drawing out the electro-deposited solution simultaneously to keep a constant circulating to obtain high purity nickel.   
   
   
       2 . The method for producing high purity nickel according to  claim 1 , characterized in that the said electrolytic solution is extracted by 3-stage countercurrent extraction at the extractant phase ratio of 1:2, and back-extract with pure water 10 mins after achieving extraction equilibrium. 
   
   
       3 . The method for producing high purity nickel according to  claim 1  or  2 , characterized in that anion extractant contains 20 vol. % to 40 vol. % tertiary amine, 20 vol. % to 45 vol. % butylate, and sulphonated kerosene. 
   
   
       4 . The method for producing high purity nickel according to  claim 1 , characterized in that it is performed before extracting NiCl2 solution that purifying the organic phase of the anion extractant by washing and sequentially saturating the said organic phase with 4N high purity hydrochloric acid. 
   
   
       5 . The method for producing high purity nickel according to  claim 1 , characterized in that a hollow fiber ball is employed to degrease the said solution.