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1. (WO2017035675) METHOD FOR REMOVING ARSENIC FROM MATERIALS CONTAINING SAME

Pub. No.:    WO/2017/035675    International Application No.:    PCT/CL2015/050038
Publication Date: Fri Mar 10 00:59:59 CET 2017 International Filing Date: Thu Sep 03 01:59:59 CEST 2015
IPC: C22B 3/12
C22B 15/00
C22B 30/04
Applicants: MOLIBDENOS Y METALES S.A.
Inventors: GRAELL MOORE, John Patrick
GUZMÁN MANZO, Manuel Enrique
PIZARRO HERRERA, Cristián Eduardo
SOTO INFANTE, Christian Ignacio
Title: METHOD FOR REMOVING ARSENIC FROM MATERIALS CONTAINING SAME
Abstract:
The invention relates to a method for removing arsenic from materials with a high arsenic and/or selenium content, comprising adding the material to a pressure reactor, adding an alkaline leaching solution, adding an oxidising gas, mixing the components in said reactor so as to produce a homogeneous pulp and subjecting said pulp to selective pressure leaching for the separation of arsenic. Said pulp is subjected to a first step of solid-liquid separation, producing an arsenic liquor and a solid with a low arsenic content. An Fe+3 and Ca+2 combination and Ce+3, Fe+3, Mg+2 precipitating agent is added to said liquor. The arsenic precipitation product is subjected to a second step of solid-liquid separation. Optionally, the method also comprises subjecting the arsenic-free alkaline liquor to a step of crystallisation of the sodium sulfate, and subjecting the product of said crystallisation (Na2S04) to a third step of solid-liquid separation.