Abstract Method for electrorefining of nickel at high current densities wherein the process is carried out by use of reverse current with a duration of the reversal electrode polarity of 3.0 to 8.0 percent of the total current period and a frequency of reversal of the poles of two to six times in a minute. The process is preferably carried out at a temperature of the solution of 50* to 80*C and with an electrolyte consisting substantially of nickel from 70 to 100 gr/l, as NiSO4; sodium chloride from 40 to 80 gr/l; sodium sulphate from 40 to 70 gr/l; and boric acid from 3 to 20 gr/l. The electrolyte is continuously agitated during the process; the process may advantageously be practiced at high current densities by apparatus capable of thoroughly and continuously circulating the electrolyte.
Method of electrorefining nickel as claimed in claim 1, wherein the process is carried out at a temperature of the solution of 50* to 80* C and with an electrolyte solution consisting substantially of nickel from 70 to 100 gr/l, sodium chloride from 40 to 80 gr/l; sodium sulphate from 40 to 70 gr/l; and boric acid from 3 to 20 gr/l.
Claim 2
Dependent Claim
23 words
Method of electrorefining nickel as claimed in claim 2, comprising circulating the solution at a rate of flow of 40 to 300 ml/Ah.
Claim 3
Dependent Claim
41 words
Method of electrorefining nickel as claimed in claim 3, comprising feeding the solution on the top of the cathode, and flowing the solution out from the bath in a self-draining condition in an upward stream by the use of a siphon.
Claim 4
Dependent Claim
40 words
Method of electrorefining nickel, as claimed in claim 1, wherein the duration of the electrode polarity reversal is about 5 percent of the total current period and the frequency of reversing the poles is about four times in a minute.
Claim 5
Dependent Claim
70 words
Method of electrorefining nickel, as claimed in claim 5, herein the process is carried out at a temperature of the solution of about 50* to 80*C, with an electrolyte solution consisting substantially of nickel of about 80 gr/l; sodium chloride of about 60 gr/l; sodium sulphate of about 60 gr/l; and boric acid of about 8 gr/l, and wherein the direct current density of about 50 amperes per square foot.
Claim 6
Dependent Claim
41 words
Method of electrorefining nickel, as claimed in claim 1, wherein the duration of the electrode polarity reversal duration is about 7 percent of the total current period and the frequency of reversing the poles is about five times in a minute.
Claim 7
Dependent Claim
70 words
Method of electrorefining nickel, as claimed in claim 7, wherein the process is carried out at a temperature of the solution of about 50* to 80*C, with an electrolytic solution consisting substantially of nickel of about 90 g/l; sodium chloride of about 70 g/l; sodium sulphate of about 80 g/l; and boric acid of about 15 g/l, and wherein the direct current density is about 100 amperes per square foot.