Production of Nickel Sulphamate (Patent No: 759370)

Inventor: Evans, David J.I.

Location: Edmonton

Comments: N/A

Description:
The embodiments of the invention in which an exclusive property or privilege is claimed, are defined as follows:

1. In a method of producing nickel sulphamate by the dissolution of nickel powder in aqueous sulphamic acid solution, the improved method whereby the rate of dissolution of the nickel powder in said solution is accelerated and hydrolysis of sulphamic acid and nickel sulphamate is minimized which comprises feeding substantially pure oxygen into a suspension of nickel powder in aqueous sulphamic acid solution while maintaining the pH of said solution below about 5.0.

2. In the method of producing nickel sulphamate by the dissolution of nickel powder in aqueous sulphamic acid solution, the improved method whereby the rate of dissolution of the nickel powder in said solution is accelerated and hydrolysis of sulphamic acid and nickel sulphamate is minimized which comprises feeding substantially pure oxygen into a suspension of nickel powder in aqueous media, maintaining the pH of said suspension in the range of about 1.5 to about 5.0 by the controlled addition of sulphamic acid.

3. The improved method of claim 2 in which the quantity of nickel in suspension and the sulphamic acid addition are controlled such that the amount of sulphamic acid available for reaction with the nickel does not exceed that required to stoichiometrically combine with the nickel.

4. The method of producing nickel sulphamate by the dissolution of nickel powder in aqueous sulphamic acid solution which comprises forming a suspension of finely divided nickel in aqueous media; adding sulphamic acid to said suspension to provide a total amount of sulphamic acid up to the stoichiometric amount required to combine with all nickel present as nickel sulphamate, the addition of sulphamic acid being controlled to maintain the pH of the suspension below about 5.0, feeding substantially pure oxygen into the suspension, continuing the dissolution reaction with active agitation and oxygenation until substantially all free sulphamic acid has reacted, and withdrawing nickel sulphamate solution.

5. The method of producing nickel sulphamate by the dissolution of nickel powder in aqueous sulphamic acid solution which comprises forming a suspension of finely divided nickel in aqueous media; adding sulphamic acid to said suspension to provide a total amount of sulphamic acid up to the stoichiometric amount required to combine with all nickel present as nickel sulphamate, the addition of sulphamic acid being controlled to maintain the pH of the suspension below about 1.5 to about 2.5, feeding substantially pure oxygen into the suspension, continuing the dissolution reaction at a temperature below about 65°C. with active agitation and oxygenation until substantially all free sulphamic acid has reacted, and withdrawing nickel sulphamate solution.


6. The method according to claim 5 in which the amount of nickel in suspension and the amount of sulphamic acid provided are controlled to maintain the amount of nickel up to 5 times in excess of the stoichiometric amount required to combine with available sulphamic acid as nickel sulphamate.

7. The method according to claim 5 in which the temperature during the dissolution reaction is controlled in the range of about 40°C. to about 60°C.

8. The method according to claim 5 in which the finely divided nickel is obtained by hydrogen reduction from aqueous media.

9. The method according to claim 5 in which the nickel sulphamate solution is separated from the undissolved nickel particles at the completion of the dissolution reaction and is then subjected, to further oxygenation to remove iron contamination by precipitation as an insoluble compound.