Sulphidization to improve the nickel oxide recovery by froth flotation

Akira Otsuki, David J. Robinson


This study aimed to investigate the sulphidization-flotation of nickel oxide. Sulphidization was conducted before froth flotation to convert the surface of nickel oxide to nickel sulphide. Key variables considered were type of sulphidization reagent, sulphidization Eh, time of sulphidization, and flotation Eh.Ammonium sulphide ((NH4)2S) was more effective in decreasing the Eh of nickel oxide suspension than sodium hydrogen sulphide (NaSH) and calcium sulphide (CaSx) and selected for sulphidization-flotation. With potassium amyl xanthate (PAX) addition, nickel oxide recovery increased after sulphidization with (NH4)2S. Increasing the time of sulphidization (> 5 min) decreased nickel oxide recovery. Flotation at Eh of –450 mV SHE produced the maximum recovery of 63%, from 37% without sulphidization (2x10-4 M PAX). The developed sulphidization-flotation method was identified as a good potential option to enhance the recovery of nickel oxide from natural ores.

Full Text:



Kongolo K, Kipoka M, Minanga K and Mpoyo M, “Improving the efficiency of oxide copper-cobalt ores flotation by combination of sulphidisers,” Minerals Engineering vol. 16, pp. 1023-1026, 2003.

Quast KB, Tsatouhas G, Wong KY and Newell R, “The use of polysulfide as an alternative sulfidising reagent for the CPS flotation of oxide copper ores,” Proc. Centenary of Flotation Symposium, Jameson, G. J. (Ed.). Brisbane, Australia, a Joint Meeting of SME and the AusIMM, pp. 1027-1032, 2005.

Barker CW, Featherstone SF and Storey MJ, “Development of flotation practice at Trojan nickel concentrator, Zimbabwe,” Trans. IMM vol.91, pp.C135-C141, 1982.

Mwema M and Mpoyo M, “Improvements of cobalt recovery in flotation of cupro-cobaltiferous ore at Gecamines,” Proc. SAIMM Copper Cobalt Nickel & Zinc Recovery Conference, Victoria Falls, Zimbabwe, SAIMM/IMM, pp. 1-9, 2001.

Newell AJH and Bradshaw DJ, “The development of a sulfidisation technique to restore the flotation of oxidised pentlandite,” Minerals Engineering vol. 20, pp.1039-1046, 2007.

Freeman WA, Newell R, Quast KB, “Effect of grinding media and NaHS on copper recovery at Northparkes mines,” Minerals Engineering vol. 13, pp.1395-1403, 2000.

Park K, Park S, Choi J, Kim G, Tong M, Kim H, “Influence of excess sulfie ions on the malachite-bubble interaction in the presence of thiol-collector,” Separation and Purification Technology vol. 168, pp.1-7, 2016.

Adkins SJ, Pears MJ, “The influences of collector chemistry on kinetics and selectivity in base-metal sulphide flotation,” Minerals Engineering vol. 5, pp.295-310, 1992.

Phetla TP, Muzenda E, “A multisage sulphidisation flotation procedure for a low grade Malachite copper ore,” Int. J. Chem. Nuclear Mater. Metallurgical Eng.,vol. 4, pp.26-32, 2010.

Bell DT, “Flotation fo cobalt bearing minerals from a mixe copper-cobalt oxidized ore,” Dissertation, Magister technology degree, University of Johannesburg, 2011.

Jacques S, “Effect of grinding chemistry on the sulphidisation and flotation performances of transitional oxide-sulphide copper ore,” PhD Thesis, University of Liége, 2017.

Ndoro TO, “Optimisation of the froth flotation process of Chingola refractory ores (CRO) by release analysis,” Master Thesis, University of Zambia, 2017.

Peng Y, Wang B and Bradshaw D, “Pentlandite oxidation in the flotation of a complex nickel ore in saline water,” Minerals Engineering vol. 24, pp.85-87, 2011.

Newell AJH, Bradshaw DJ and Harris, PJ, “The effect of heavy oxidation upon flotation and potential remedies for Merensky type sulfides,” Minerals Engineering vol. 19, pp.675-686, 2006.

Newell AJH, Skinner WM and Bradshaw DJ, “Restoring the floatability of oxidised sulfides using sulfidisation,” Minerals Engineering vol.20, pp.108-117, 2007.

Siame E, “The role of pulp chemistry in the flotation recovery of Nchanga underground copper ore”, Master thesis, University of Cape Town, 2000.

Clark DW, Newell AJH, Chilman GF and Capps PG, “Improving flotation recovery of copper sulphides by nitrogen gas and sulphidisation conditioning,”Minerals Engineering pp.13 pp.1197-1206, 2000.

Soto H and Laskowski J, “Redox conditions in the flotation of malachite with a sulphidizing agent,” Trans. IMM. vol.82, pp.C153-157, 1973.

Parks GA, “The isoelectric points of solid oxides, solid hydroxides, and aqueous hydroxo complex systems,” Chem. Rev. vol.65, pp.177– 197, 1965.

Naklicki ML, Rao SR, Gomez M and Finch JA, “Flotation and surface analysis of the nickel (II) oxide/amyl xanthate system,” Int. J. Miner. Process. vol.65, pp.73-82, 2002.

Rao SR and Finch JA, “Base metal oxide flotation using long chain xanthates,” Int. J. Miner. Process. vol.69, pp.251-258, 2003.

Bultovic S, “Flotation of oxide copper and copper cobalt ores,” In Handbook of flotation reagents: chemistry, theory and practice, vol.2, pp.47-65, Elsevier Science and Technology, 2010.

Anfruns J and Kitchener J, “Rate of capture of small particles in flotation,” J. Trans IMM, vol.86, pp.C9-C15, 1977.

Wills B, Mineral Processing Technology 6th Edition. London: Butterworth Heinemann, 1997.


  • There are currently no refbacks.

MAYFEB Journal of Chemistry and Chemical Engineering


Toronto, Ontario, Canada

ISSN 2560-693X