Abstract
The processing of nickel by pressure acid leaching nickel laterite ores at 250 °C results in liquors supersaturated with respect to aluminum, iron, and silica. These can precipitate from the liquor and onto the autoclave interior (scaling). This reduces the availability of the autoclave. This article presents a methodology for characterizing scale using X-ray powder diffraction (XRPD), Rietveld analysis of the XRPD trace, and scanning electron microscopy/microprobe. This methodology is then used to characterize three scales formed during the continuous (pilot plant) pressure acid leaching of nickel laterites. Scales formed during the leaching of Western Australian ore, from an acid environment in hypersaline process water, contain mainly sodium alunite/jarosite as a solid solution together with minor hematite and amorphous silica. Scales formed during leaching of tropical nickel laterite, in low salinity process water, consist of an aluminum-rich hydronium alunite with hematite and low concentrations of amorphous silica. Ore mineralogy, leach liquor composition, acidity, and temperature, as well as precipitation kinetics, all appear to influence the scale mineralogy. This article discusses the influence of these factors on the formation of three scales.
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References
S.I. Sobol: Revista Technologica, 1966, vol. 4 (4), pp. 3–19.
S.I. Sobol: Revista Technologica, 1969, vol. 7, p. 3.
C. Czerny and B. Whittington: ALTA 1999 Nickel/Cobalt Pressure Leaching and Hydrometallurgy Forum, ALTA Metallurgical Services, Melbourne, 1999.
B.I. Whittington and D. Muir: Min. Proc. Extr. Met. Rev., 2000, in press.
S.A. Makhmudov and C.M. Kashkai: Tr. Azerb. Otd. Vses. Mineral. O-va, 1981, No. 2, pp. 68–72.
G.K. Das, S. Acharya, S. Anand, and R.P. Das: Min. Pro. Ext. Met. Rev., 1996, vol. 16, pp. 185–210.
U. Schwertmann and R.M. Cornell: Iron Oxides in the Laboratory: Preparation and Characterisation, VCH Verlagsgesellschaft mbH, Weinheim, 1991, p. 7.
E.H. Kisi: Materials Forum, 1994, vol. 18, pp. 135–53.
L.B. McCusker, R.B. von Dreele, D.E. Cox, D. Louer, and P. Scardi: J. Appl. Cryst., 1999, vol. 32, pp. 36–50.
R.J. Hill: in Advances in X-ray Analysis, C.S. Barret, J.V. Gilfrich, T.C. Huang, R. Jenkins, G.J. McCarthy, P.K. Predecki, R. Ryon, and D.K. Smith, eds., Plenum Press, New York, NY, 1992, pp. 25–38.
S. Menchetti and C. Sabelli: Neues Jb. Miner. Mh., 1976, pp. 406–17.
K. Okada, J.-I. Hirabayashi, and J. Ossaka; Neues Jb. Miner. Mh., 1982, pp. 534–40.
M.G. Aylmore and G.S. Walker: Powder Diffraction, 1998, vol. 13, pp. 136–43.
U. Schwertmann: In Iron in Soils and Clay Minerals, J.W. Stucki, B.A. Goodman, and U. Schwertmann eds., D. Riedel Publishing Company, Dordrecht, 1988, pp. 203–50.
K. Tozawa and K. Sasaki: in Iron Control in Hydrometallurgy, J.E. Dutrizac and A.J. Monhemius, eds., Ellis Horwood, Chichester, United Kingdom, 1986, pp. 454–76.
G.P. Tindall and D.M. Muir: Proc. Nickel-Cobalt 97 Int. Symp., Sudbury, ON, Canada, W.C. Cooper and I. Mihaylov, eds., Canadian Institute of Mining, Metallurgy and Petroleum, Montreal, 1997, pp. 459–70.
Note added in proof. Scaling in the autoclaves of the three Western Australian processing plants has been discussed by C. Czerny and B. Whittington: ALTA 2000.
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Whittington, B.I. Characterization of scales obtained during continuous nickel laterite pilot-plant leaching. Metall Mater Trans B 31, 1175–1186 (2000). https://doi.org/10.1007/s11663-000-0004-4
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DOI: https://doi.org/10.1007/s11663-000-0004-4