Patent ID: 8147779
Filing Date: 2012-04-03
Classification: C01G,C01P,C02F,C22B,Y02P

Abstract:
1. A method of processing a substance that contains diarsenic trioxide and heavy metal, comprising: a leaching step of adding water and NaOH to a non-ferrous smelting intermediate that contains diarsenic trioxide and heavy metal to produce slurry, heating the slurry, and leaching arsenic at a pH of not less than 8 so as to obtain leachate; a solution adjusting step of adding hydrogen peroxide to the leachate to oxidize trivalent arsenic to pentavalent arsenic so as to obtain an adjusted solution; and a crystallizing step of converting arsenic in the adjusted solution to scorodite crystals, wherein hydrogen peroxide remaining in the adjusted solution is removed by bringing the remaining hydrogen peroxide into contact with metallic copper.