Method for extracting tungsten from scheelite

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United States of America Patent

PATENT NO 8771617
APP PUB NO 20130195737A1
SERIAL NO

13794844

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Abstract

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A method for extracting tungsten from scheelite by: 1) adding a mixed acid including H2SO4 and H3PO4 to a decomposition reactor; 2) heating the mixed acid to a temperature of 70-100° C.; adding scheelite while controlling the mixed acid present in an amount of 3-8 L per kg of scheelite; allowing the components in the decomposition reactor to react for 1-6 h, and filtering the resulting mixture to obtain a filtrate; 3) supplementing the filtrate with sulfuric acid consumed in the reaction; 4) crystallizing the filtrate to obtain phosphotungstic acid crystals and mother liquor; 5) dissolving the phosphotungstic acid crystals in water to obtain a phosphotungstic acid solution; 6) transforming the phosphotungstic acid solution into an ammonium tungstate solution for the purpose of preparing ammonium paratungstate; and 7) supplementing the mother liquor with phosphoric acid and water to an initial level and reusing the mother liquor for ore leaching.

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Patent Owner(s)

Patent OwnerAddress
CENTRAL SOUTH UNIVERSITYYUELU DISTRICT CITY HUNAN PROVINCE 410083 CHANGSHA LUSHAN ROAD NO 932 CHANGSHA CITY HUNAN PROVINCE 410083

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Inventor(s)

Inventor Name Address # of filed Patents Total Citations
Li, Jiangtao Changsha, CN 55 1189
Zhao, Zhongwei Changsha, CN 22 13

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