METHOD OF TREATING ARSENICAL MATTER WITH ALKALI

• Main Authors: ABUMIYA MITSUO, SATO YUSUKE, MATSUMOTO MASAYOSHI, MIKAMI HIRONOBU, OOUCHI MASAMI, FUJITA TETSUO
• Format: Patent
• Language: English; Korean
• Published: 12.05.2010
• Subjects: CHEMISTRY; COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSESC01D OR C01F; DISPOSAL OF SOLID WASTE; FERROUS OR NON-FERROUS ALLOYS; INORGANIC CHEMISTRY; METALLURGY; PERFORMING OPERATIONS; PRETREATMENT OF RAW MATERIALS; PRODUCTION AND REFINING OF METALS; RECLAMATION OF CONTAMINED SOIL SOIL; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS

A method that in the treatment of arsenic contained in nonferrous smelting intermediate products, especially the treatment of arsenic existing in the form of diarsenic trioxide, satisfies the elution standards (according to Notification No. 13 from the Environment Agency), ensures excellence in filtration and can form stable scorodite readily with high reproducibility without any complex operation. There is disclosed a method of treating diarsenic trioxide, comprising the leaching step of adding water and an alkali to a nonferrous smelting intermediate product containing diarsenic trioxide into a slurry, warming the slurry and leaching out arsenic; the liquid preparation step of adding an oxidizing agent to the leach liquor so as to oxidize the trivalent arsenic to pentavalent arsenic, thereby obtaining a preparation liquid; and the crystallization step of converting the arsenic contained in the preparation liquid to a scorodite crystal.