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Sulphur-Mediated Precipitation of Pt/Fe/Co/CrIons in Liquid-Liquid and Gas-Liquid Chloride Systems

Authors: J. Siame, H. Kasaini

Abstract:

The proof of concept experiments were conducted to determine the feasibility of using small amounts of Dissolved Sulphur (DS) from the gaseous phase to precipitate platinum ions in chloride media. Two sets of precipitation experiments were performed in which the source of sulphur atoms was either a thiosulphate solution (Na2S2O3) or a sulphur dioxide gas (SO2). In liquid-liquid (L-L) system, complete precipitation of Pt was achieved at small dosages of Na2S2O3 (0.01 – 1.0 M) in a time interval of 3-5 minutes. On the basis of this result, gas absorption tests were carried out mainly to achieve sulphur solubility equivalent to 0.018 M. The idea that huge amounts of precious metals could be recovered selectively from their dilute solutions by utilizing the waste SO2 streams at low pressure seemed attractive from the economic and environmental point of views. Therefore, mass transfer characteristics of SO2 gas associated with reactive absorption across the gas-liquid (G-L) interface were evaluated under different conditions of pressure (0.5 – 2 bar), solution temperature ranges from 20 – 50 oC and acid strength (1 – 4 M, HCl). This paper concludes with information about selective precipitation of Pt in the presence of cations (Fe2+, Co2+, and Cr3+) in a CSTR and recommendation to scale up laboratory data to industrial pilot scale operations.

Keywords: CSTR, diffusivity, platinum, selective precipitation, sulphur dioxide, thiosulphate.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1073421

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References:


[1] S. Ebrahimi, R. Kleerebezem, M. C. M. van Loosdrecht, and J. J. Heijnen, "Kinetics of the reactive absorption of hydrogen sulphide into aqueous ferric sulphate solutions," Chem. Eng. Sci., vol. 58, pp. 417 - 427, 2003.
[2] H. Ter Maat, J. A. Hogendoorn, and G. F. Versteeg, "The removal of hydrogen sulphide from gas stream using an aqueous metal sulphate absorbent. Part I. The absorption of hydrogen sulphide in metal sulphate solutions," Sep. Purif. Technol., vol. 43, pp. 183 - 197, 2005.
[3] M. Al-Tarazi, A. B. M. Heesink, and G. F. Versteeg, "Precipitation of metal sulphides using gaseous hydrogen sulphide: mathematical modelling," Chem. Eng. Sci., vol. 59, pp. 567 - 579, 2004.
[4] N. Karbanee, "Investigation towards controlled precipitation of nickel using H2S gas by harnessing pH dependent sulphide speciation," M.Sc in Eng. Thesis, University of Cape Town, South Africa, 2007, unpublished.
[5] V. Menard, and G. P. Demopoulos, "Gas transfer kinetics and redox potential consideration in oxidative precipitation of manganese from an industrial zinc sulphate solution with SO2/O2," Hydrometallurgy, vol. 89, pp. 357 - 368, 2007.
[6] F. L. Bernardis, R. A. Grant, and D. C. Sherrington, "A review of methods of separation of the platinum-group metals through their chloro-complexes," React. & Fun. Poly., vol. 65, pp. 205 - 217, 2005.
[7] D. Dreisinger, W. Murray, D. Hunter, K. Baxter, J. Ferron and C. Fleming," The Application of the PLATSOL™ Process to Copper- Nickel-Cobalt-PGE/PGM Concentrates from PolyMet Mining's NorthMet Deposit", Presented at ALTA 2005, Perth, WA, May, 2005, unpublished.
[8] H. Kasaini, "Enrichment process for PGM-metals containing stream," South Africa Patent PCT/ZA2008/000067, July 28, 2008.
[9] J. I. Kroschwitz and M. Howe-Grant,"Encyclopaedia of chemical technology, Kirk-Othmer 4th ed.," Wiley & Sons. New York, 1991.
[10] K. K. Mishra and M. L. Kapoor, "Kinetics of liquid-gas reactions through bubbles," Hydrometallurgy, vol. 3, pp. 75-83, 1978.
[11] R. Higbie, "The rate of absorption of a pure gas into a still liquid during short periods of exposure," Trans. Am. Inst. Chem. Eng., Vol. 35, pp. 36-60, 1935.
[12] C. Oktaybas, E. Acma, C. Arslan, and O. Addemir, "Kinetics of copper precipitation by H2S from Sulphate solutions," Hydrometallurgy, vol. 35, pp. 129-37, 1994.
[13] R. R. Broekhuis, D. J. Koch, and S. Lynn,"A medium temperature process for removal of hydrogen sulphide from sour gas streams with aqueous metal sulphate solutions," Ind. Eng. Chem. Res., vol. 31 pp. 2635-42, 1992.
[14] H. Maat Ter, J. A. Hogendoorn, and G. F. Versteeg,"The removal of hydrogen sulphide from gas stream using an aqueous metal sulphate absorbent: Part I The absorption of H2O in metal sulphate solutions," Separation and Purification Technology, vol. 4, pp. 183 - 197, 2005
[15] F. Habashi, "Principles of Extractive Metallurgy, Vol. 2" Gordon and Breach, Science Publishers, Inc. New York, pp. 203, 1970.
[16] G. Schreier, and C. Edtmaier, "Separation of Ir, Pd, and Rh from secondary Pt scrap by precipitation and calcinations," Hydrometallurgy, vol. 68, pp. 69 - 75, 2003.
[17] H. G. Julsing, and R. I. McCrindle, "The use of sodium formate for the recovery of precious metals from acidic base metal effluents," Journal of Chem. Technol. & Biotechnology., vol. 76(4), pp. 349 - 354(6), 2001.
[18] H. Kasaini, R. C. Everson, and O. S. L. Bruinsma, "Selective Adsorption of Platinum from Mixed solutions Containing Base Metals Using Chemically Modified Activated Carbons," Separation Science and Technology, vol. 40, pp. 507 - 523, 2005.
[19] A. E. Nielsen, "Kinetics of nucleation," Pergamon Press Ltd.
[20] O. Söhnel, and J. Garside, "Precipitation, basic principles and industrial Applications," Butterworth Heinemann Ltd., Oxford.
[21] O. Levenspiel, "Chemical Reaction Engineering, 3rd ed.," John Wiley & Sons, Inc., New York, 1999, pp. 38 - 76.
[22] Y. E. Kenig, U. Wiesner, and A. Gorak, "Modelling of reactive Absorption Using the Maxwell-Stefan Equations," Ind. Eng. Chem. Res., vol. 36, pp. 4325 - 4334, 1997.
[23] L. Rodriguez-Sevilla, M. Alvarez, G. Liminana, and M. C. Diaz, "Dilute SO2 Absorption Equilibrium in Aqueous HCl and HCl Solution at 298.15 K," J. Chem. Eng. Data, vol. 47, pp. 1339 - 1345, 2002.
[24] V. M. Dagaonkar, A. A. C. M. Beenackers, and V. G. Pangarkar, "Enhancement of gas-liquid mass transfer by small reactive particles at realistically high mass transfer coefficients: absorption of sulphur dioxide into aqueous slurries of Ca(OH)2 and Mg(OH)2 particles," Chem. Eng. J., vol. 81, pp. 203 - 212, 2001.
[25] H. Kasaini, M. Goto, and S. Furisaki, "Separation of Pd(II), Rh(III) and Ru(III) ions from a Mixed Chloride Solution Using Activated Carbon Pellets," Sep. Sci. Technol., vol.35(9), pp. 1307 - 1327, 2000.
[26] H. Kasaini, R. C. Everson, and O. S. L. Bruinsma, "Selective Adsorption of Platinum from mixed Solution Containing Base Metals using Chemically Modified Activated Carbons," Sep. Sci. Technol., vol. 40, pp. 507 - 523, 2005.
[27] M. Cox, "Solvent Extraction in Hydrometallurgy, Principles and Practices," In Principles and Practices of Solvent Extraction; J. Rydberg, C. Musikas, G. R. Choppin, Eds.; Marcel Dekker, Inc.: New York, pp. 381 - 393, 1992.
[28] M. Cox, "Liquid-Liquid Extraction in Hydrometallurgy," In Science and Practice of Liquid-Liquid Extraction; Thornton, J. D., Ed.; Clarendon Press: Oxford 2, pp. 57, 1992.
[29] A. Koliadima, J. Kapolos, and L. Farmakis, "Diffusion Coefficients of SO2 in Water and Partition Coefficients of SO2 in Water-Air Interface at Different Temperature and pH Values," Instrument. Sci. And Technol., vol. 37, pp. 274 - 283, 2009.
[30] D. G. Leaist, "Diffusion Coefficient of Aqueous Sulphur Dioxide at 25┬░C," J. Chem. Eng. Data, vol. 29, pp. 281 - 282, 1984.
[31] J. Boniface, Q. Shi, Y. Q. Li, J. L. Cheung, O. V. Rattigan, P. Davidovits, D. R. Worsnop, S. T. Jayne, and C. E. Kolb, " Uptake of gas-phase SO2, H2S and CO2 by aqueous solutions," J. Phys. Chem. A vol. 104 (32), pp. 7502-7510, 2000.