Arsenic leaching recovery method from non-ferrous smelting ash

摘要

PROBLEM TO BE SOLVED: To provide a method for leaching arsenic from nonferrous smelting smoke ash capable of recovering almost all arsenic as a pentavalent arsenic solution without using a sulfidizing agent, and restraining copper from being mixed into the arsenic solution in recovering arsenic from nonferrous smelting smoke ash.SOLUTION: The method for leaching arsenic from nonferrous smelting smoke ash includes a step for slurrying the nonferrous smelting smoke ash, a step for adding alkali to the slurry and performing leaching to obtain primary leaching residues, a step for adding acid to the primary leaching residues and performing leaching to obtain a secondary leaching liquid, a step for neutralizing the secondary leaching liquid by adding alkali, a step for obtaining a liquid after the neutralization from the obtained slurry and obtaining oxidative leaching residues by adding an oxidizing agent to the liquid after the neutralization after a neutralizing agent is added, and performing oxidative leaching, and the third leaching step for adding acid to the oxidative leaching residues and obtaining the arsenic solution for producing crystalline iron arsenate as a leaching solution.