Abstract
Presented is a thermodynamic feasibility analysis of extracting base metal chlorides from low-grade, multi-metallic oxide ores using CaCl2 as a chlorinating agent in the presence of SO2 and O2. The oxides react to form corresponding chlorides, while CaCl2 is converted to CaSO4. The Ellingham diagram is used for comparing the standard Gibbs’ free energy change for the sulfation-chlorination reaction of a large number of oxides. Except for alumina, silica and chromia, most of the other metal oxides will be converted to their respective chlorides. The volatile chlorides can be condensed, and the chlorides present in the condensed state can be leached. A process is proposed that uses a nontoxic chlorinating agent and gives an efficient separation of the metallic values from the gangue.
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References
Chase, M.W., et al., 1985, “JANAF thermochemical tables,” 3rd ed., Suppl. No. 1, Journal of Physical and Chemical Reference Data. 14.
Ngoc, N.V., Shamsuddin, M. M. and Prasad, P.M., 1989, “Salt roasting of an off-grade copper concentrate,” Hydrometallurgy, Vol. 21, pp. 359–372.
Pankratz, L.B., 1984, “Thermodynamic properties of halides,” USBM Bulletin 674.
Pankratz, L.B., 1982, “Thermodynamic properties of elements and oxides,” USBM Bulletin 672.
Rajmohan, N., and Jacob, K.T., 1992, “The combined sulphation/chlorination roasting of oxides,” Minerals Engineering, Vol. 5, pp. 235–243.
Stern, K.H., and Weise, E.L., 1966, “High temperature properties and decomposition of inorganic salts,” US Department of Commerce, National Standard Reference Data Series, National Bureau of Standards, 7.
Weast, R.C., Astle, M.J., and Beyer, W.H., 1987–1988, Handbook of Chemistry and Physics, 68th ed., CRC Press, Boca Raton, FL.
Wicks, C.E., and Block, F.E., 1963, “Thermodynamic properties of 65 elements — Their oxides, halides, carbides and nitrides,” USBM Bulletin 605.
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SME nonmeeting paper 91-649.
Discussion of this paper must be submitted, in duplicate, prior to Nov. 30, 1992.
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Rajmohan, N., Jacob, K.T. Use of CaCl2 as a chlorinating agent for oxides — A thermodynamic analysis. Mining, Metallurgy & Exploration 9, 141–145 (1992). https://doi.org/10.1007/BF03402986
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DOI: https://doi.org/10.1007/BF03402986