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US 6,387,240 B1Granted
Method for the removal of sulfur in the nickel leaching process
AssigneeOutokumpu Oyj
InventorLeif Rosenback
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Abstract
Invention relates to a method for the removal of sulfur from the leaching cycle of nickel processes such as leaching of nickel matte. According to the method, anolyte generated in nickel electrowinning is neutralized with the aid of a calcium-based neutralizing agents, wherein sulfur is removed from the leaching cycle as gypsum.
Claims13
A method for removing sulfur generated in leaching of nickel matte from a leaching cycle of the nickel matte, which method comprises leaching the nickel matte in several steps with an anolyte of a nickel electrolysis to form a nickel sulfate solution;
- purifying the nickel sulfate solution and subjecting the purified nickel sulfate solution to the nickel electrolysis to recover elemental nickel and the anolyte containing the sulfur of the nickel matte as sulfuric acid;
- neutralizing part of the sulfuric acid of the anolyte in a neutralization step with a calcium-based neutralizing agent to produce a solution that is saturated with gypsum;
- and removing gypsum from the gypsum saturated solution before recycling the neutralized anolyte to the leaching cycle.
Dependencies are inferred from the claim text.