000 02492cam  2200337za 4500
0019.840315
003CaOODSP
00520221107151819
007cr |||||||||||
008170725s1967    onc     ob   f000 0 eng d
040 |aCaOODSP|beng
043 |an-cn---
0861 |aM38-8/34E-PDF|zM38-8/34
1001 |aVezina, J. A.
24512|aA process for preparing tungstic trioxide of high purity from a Canadian scheelite concentrate |h[electronic resource] / |cJ.A. Vezina and W.A. Gow, Extraction Metallurgy Division.
260 |aOttawa : |bQueen's Printer, |c1967.
300 |ap. 1418-1422
4901 |aReprint series ; |vRS 34
500 |aCover title.
500 |a"Reprinted from The Canadian Mining and Metallurgical Bulletin, December 1966, Vol. 59, No. 656, pp. 1418-1422."
500 |aHistorical publication digitized from print 2017 [by Natural Resources Canada].
504 |aIncludes bibliographical references.
5203 |a"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.
69207|2gccst|aChemicals
69207|2gccst|aProcessing
7001 |aGow, W. A.
7101 |aCanada. |bNatural Resources Canada.
7101 |aCanada. |bDepartment of Energy, Mines and Resources.
7101 |aCanada. |bMines Branch.
830#0|aReprint series - Dept. of Energy, Mines and Resources, Mines Branch ;|vRS 34|w(CaOODSP)9.834843
85640|qPDF|s1.98 MB|uhttps://publications.gc.ca/collections/collection_2017/rncan-nrcan/M38-8/M38-8-34-eng.pdf