Processing of low grade tungsten ore concentrates by hydrometallurgical route with particular reference to India
- 226 Downloads
Tungsten, because of its high strength and high melting point occupies a prime position amongst metals. With depletion of high grade resources considerable R and D work is still being carried out in tungsten producing countries around the world for the processing of low grade and secondary resources. The paper gives a brief review of the hydrometallurgical processes developed to recover tungsten from low grade concentrates.
The R and D work carried out on purification and recovery of tungsten as tungstic oxide/ammonium paratungstate (APT) from a number of off-grade products such as table concentrate (WO3=66%, SiO2=2·2%, S=1·8%), middlings (18–20% WO3, and 28–30% S) and jig concentrate (4·6% WO3) are discussed in this paper. It has been found that more than 75% of silica and 90% of sulphur could be removed from the table concentrate by curing with hydrofluoric acid and subsequent roasting of the desilicated product at 650°C. In the case of middlings, it was possible to recover over 90% of tungsten as tungstic oxide by an oxidative roast followed by pressure leaching with soda.
A detailed study on the low grade jig concentrate to recover tungsten as APT, showed that over 90% extraction was possible by adopting the pressure leaching-solvent extraction route. Effect of parameters such as soda concentration, time, temperature and pressure during leaching; as well as extraction and stripping behaviour of tungsten from leach solution at different pH and aqueous to organic ratio during solvent extraction with Alamine-336, were studied and a flow-sheet was developed for processing of jig concentrate analysing 4·6% WO3.
KeywordsLow grade concentrate pressure leaching purification of concentrate and leach solution solvent extraction APT crystallization
Unable to display preview. Download preview PDF.
- Bhat T R and Gokhale Y W 1966 BARC Report No. A.E.E.T/251Google Scholar
- Bhosale S N, Mookherjee S and Pardeshi R M 1990High Temp. Mater. & Processes 9 147Google Scholar
- Churchward P E and Bridges D W 1966 US Bureau of Mines, Report of Investigation, p. 6845Google Scholar
- Drobnik J L and Lewis C J 1962 US Patent 3, 052, 516Google Scholar
- Gokhale Y W and Gupta S S 1968 Report No. BARC, p. 380Google Scholar
- Hamilton E M 1918 US Patent 1, 261, 383Google Scholar
- Honggui Li, Maosheng Liu and Yunjiao Li 1987 W-Ti-Re-Sb 88,Proc. of the 1st international conference on metallurgy and material science, 2, p. 192Google Scholar
- Hughes M A and Hanson C 1983Proc. symp. hydrometallurgy — research, development and plant practice (eds) Osseo-Asare and Miller (TMS/AIME), pp 491–501Google Scholar
- John E Litz 1981Extractive metallurgy of refractory metals, Proc. symp. (eds) H Y Sohn, Norman Carlson and J Thomas Smith (TMS/AIME), pp 69–81Google Scholar
- Konishi Y, Katada H and Asai S 1986Metall. Trans. B18 331Google Scholar
- Lassner E 1982Proc. of second international tungsten symposium, San Francisco, p. 71Google Scholar
- Li K C 1962J. Metals 14 413Google Scholar
- Li K C and Wang Chung Yu 1956Tungsten (New York: Reinhold Publishing Corporation), 3rd ed. p. 166Google Scholar
- MacInnis M B and Kim T K 1983Handbook of solvent extraction (eds) T C Lo, M H I Baird and C Hanson (New York: John Wiley), p. 689Google Scholar
- Marshall R E 1983Proc. Aust. Inst. Min. Metall. 325Google Scholar
- Maslenitsky N N and Perlov P M 1960 Ch. inInternational mineral processing congress 1959 (London: Institution of Mining and Metallurgy), p. 839Google Scholar
- Qixiu Z, Bofan G, Welzhuang H and Shaoying H 1988 Research Institute of Non-ferrous Metallurgy, Central-South University of Technology, Changsha, PRC, p. 97Google Scholar
- Queneau P and Cooke S R B 1969TMS-AIME Trans. 254 2541Google Scholar
- Queneau P B, Huggins D K and Beckstead L W 1981Extractive metallurgy of refractory metals, Proc. of symp. of the metallurgical society of AIME, p. 237Google Scholar
- Shamsuddin M and Sohn H Y 1981Extractive metallurgy of refractory metals, Proc. symp. TMS/AIME (eds) Sohn, Carlson and Smith, p. 205Google Scholar
- Subramanian C, Suri A K and Gupta C K 1992Trans. The Indian Institute of Metals 45 207Google Scholar
- Yih S W H and Wang C T 1979Tungsten (New York: Plenum Press) 1st ed., p. 89Google Scholar
- Zhou Ju-Qin and Xue Jian 1990Proc. of fifth international tungsten symposium, Budapest, p. 79Google Scholar