A process for preparing tungstic trioxide of high purity from a Canadian scheelite concentrate: M38-8/34E-PDF

"A new process for treating scheelite for the production of tungstic trioxide is described. The novelty of the process resides in that an ion-exchanger is used to convert sodium tungstate to either ammonium tungstate or tungstic acid. The process consists of a conventional hydrochloric acid leach of the scheelite concentrate, and the dissolution of the impure tungstic acid thus produced with sodium hydroxide at pH 8. The sodium tungstate solution is clarified and passed through a column of Dowex 50Wx8 ion-exchange resin to exchange the sodium ions for either hydrogen or ammonium ions, both being suitable. The tungsten-bearing column effluent is evaporated to crystallize the tungsten as ammonium tungstate; the crystals are washed with nitric acid and water and decomposed by heat to produce tungstic trioxide of high purity. Ninety-six per cent of the tungsten in the concentrate may be recovered as tungstic trioxide (WO3), and the reagents consumed are 0.7 g HC1, 0.41 g NaOH and either 1.73 g NH4CI or 225 g HCl per gram of tungsten"--Abstract, p. 1418.

Permanent link to this Catalogue Record: What is a permanent link?
http://publications.gc.ca/pub?id=9.840315&sl=0
MARC XML Format   MARC HTML Format

Department/Agency Natural Resources Canada. Dept. of Energy, Mines and Resources. Mines Branch.
Title A process for preparing tungstic trioxide of high purity from a Canadian scheelite concentrate
Series Title Reprint series ;
Publication Type Series - View Master Record
Language [English]
Format Electronic
Electronic Document

Archived Content

Information identified as archived is provided for reference, research or recordkeeping purposes. It is not subject to the Government of Canada Web Standards and has not been altered or updated since it was archived. Please contact the authoring department to request a format other than those available.

We invite you to consult the Frequently Asked Questions page for additional information regarding the Archived Content notice.


Having trouble opening this document?

Note: The URLs contained in this/these document(s) may no longer be functional
Note Cover title. "Reprinted from The Canadian Mining and Metallurgical Bulletin, December 1966, Vol. 59, No. 656, pp. 1418-1422." Historical publication digitized from print 2017 [by Natural Resources Canada].
Date 1967.
Number of Pages p. 1418-1422
Catalogue Number
  • M38-8/34E-PDF
Departmental Catalogue Number 300113
Subject Terms Chemicals, Processing