00000nam 2200000za 4500 9.841314 CaOODSP 20221107152045 cr ||||||||||| 170809s1970 onc ob f000 0 eng d CaOODSP eng eng fre n-cn--- M34-20/104E-PDF M34-20/104 Vezina, J. A. Improvement of a continuous process for the production of tungstic trioxide from scheelite [electronic resource] : preleaching the scheelite with weak hydrochloric acid / J.A. Vezina and W.A. Gow, Extraction Metallurgy Division. Ottawa : Queen's Printer, 1970. iv, 7 p. Technical bulletin ; TB 104 Cover title. "December 1969." Digitized edition from print [produced by Natural Resources Canada]. Includes bibliographical references. “The effect of leaching Canadian scheelite concentrates with weak hydrochloric acid at pH 1.0 prior to treatment by a previously described Mines Branch process was investigated. The work showed that the weak-acid leach removed about 25 per cent of the iron, 90 per cent of the phosphorus, 10 per cent of the calcium and 0.1 per cent of the tungsten from a scheelite concentrate analysing 54.4 per cent WO3 , 15.8 per cent CaO, 3.9 per cent Fe, and 0.43 per cent P. The overall cost on the basis of acid consumption and tungsten loss would be about $0.04 less per pound of tungsten than for the original Mines Branch process where the weak-acid leach was not used"--Abstract, p. i. Includes abstract in French. gccst Chemicals gccst Processing Gow, W. A. Canada. Natural Resources Canada. Canada. Mines Branch. Technical bulletin (Canada. Dept. of Energy, Mines and Resources. Mines Branch) TB 104 (CaOODSP)9.834857 PDF 1.34 MB https://publications.gc.ca/collections/collection_2017/rncan-nrcan/M34-20/M34-20-104-eng.pdf 299990