Patent ID: 8277633

Claim:
A process for recycling a post-scorodite-synthesis solution, comprising the steps of: (1) conducting a sulfuric acid leaching by feeding an oxygen-containing gas into an electrolytically precipitated copper in an acidic aqueous solution of sulfuric acid, while stirring the solution at a temperature and for a time sufficient for oxidizing As component contained in the electrolytically precipitated copper to pentavalent, followed by solid-liquid-separation of the solution into a post-leaching residue and a sulfuric acid-leached solution containing the pentavalent As component, (2) adding ferric sulfate into said sulfuric acid-leached solution so that the molar ratio of trivalent Fe to pentavalent As may be equal to or more than 0.9 and equal to or less than 1.1 to prepare a reaction solution, followed by synthesis of a crystalline scorodite, (3) after the synthesis of the scorodite, conducting solid-liquid-separation of the reaction solution into a post-scorodite-synthesis solution and a scorodite crystal, and (4) using the post-scorodite-synthesis solution directly as an electrolyte solution used in electrolytic refining of copper.