Mathias Nibebaar Aakyiir


Experimental work and analysis have been carried out in this investigation to ascertain the effect of locally produced saltpetre in the Ghanaian market on gold dissolution rate and recovery. The locally produced saltpetre has been used in this study as a potential oxidising agent and its performance compared with already existing oxidising agents (hydrogen peroxide and air) in gold cyanidation process. The cyanidation test was conducted on a free milling, oxide gold ore. The outcome of the leaching test showed that saltpetre could be used as an oxidant for gold cyanidation. A maximum Au recovery of 98% was obtained after 24 hours of cyanide leaching for all oxidising agents. Hydrogen peroxide however, proved to be a better oxidant than saltpetre in terms of leaching kinetics. The slow leaching kinetics for the saltpetre when compared to H2O2 is attributed to the low purity of saltpetre. Saltpetre also proved to be a better pH modifier in terms of alkalinity, compared to the normally used lime in the gold industry. The pH modifying ability of saltpetre despite its natural pH of about 7 is attributed to its dissociation in water to produce potassium hydroxide (KOH), a good pH modifier. 


Saltpetre, Potassium Nitrate, Hydrogen Peroxide, Leaching, Gold, Cyanidation.

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Arslan, F., Ozdamar, D. and Muduroglu, M., (2003), "Cyanidation of Turkish Gold-Silver Ore and the use of Hydrogen Peroxide", The European Journal of Mineral Processing and Environmental Protection, 3(3), pp. 309-315.

Esmkhani, R., Ghobadi, B., Amirkhani, A. and Rezadust, S., (2013), "The Effect of Increasing Capacity on Gold Recovery and Optimization of Cyanidation Parameters in Aghdarreh Gold Ore Plant", Australian Journal of Basic and Applied Sciences, 2(7), pp. 702-708.

Guzman, L., Segarra, M., Chimenos, J.M., Fernandez, M.A. and Espiell, F., (1999), "Gold Cyanidation using Hydrogen Peroxide", Hydrometallurgy, 52(1), pp. 21-35.

Knoore, H., Loroesch, J., Gos, S. and Stoll, M. Z. A., (1993), "Process for Leaching Precious Metals with Hydrogen Peroxide and Cyanide Leaching Solution", Australian Journal of Basic and Applied Sciences, pp. 1-23.

Knoore, H. and Griffiths, A., (1984), "Cyanide Detoxification with Hydrogen Peroxide using the Degusaa Process", Tucson, pp. 1-11.

Kondos, P.D., Deschenes, G. and Morrison, R.M., (1995), "Process Optimization Studies in Gold Cyanidation", Hydrometallurgy, 39(1-3), pp. 235-250.

Kondos, P.D., Griffith, W.F. and Jara, J.O., (1996), "The use of Oxygen in Gold Cyanidation", Canadian Metallurgical Quarterly, 35(1), pp. 39-45.

Krauskopf, K.B., (1951), "The Solubility of Gold", Economic Geology, 46(8), pp. 858-870.

Kydryk, V. and Kellog, H. H., (1954), "Mechanism and Rate-controlling in the Dissolution of Gold in Cyanide Solution", Metal Journal, Volume 6, pp. 51-58.

Ling, P., Thaus, J. and Korey, L., (1996), "An Improved Rate Equation for Cyanidation of a Gold Ore", Randol Gold Forum, pp. 124-134.

Loroesch, J., (1990), "Peroxide-Assisted Leach: Three Years of Increasing Success", Randol Gold Forum, pp. 215-219.

Marsden, J. O. and House, I. (2006), "The Chemistry of Gold Extraction", SME, Colorado-USA, (2nd ed.), 651 pp.

Medieval Gunpowder Research Group (MGRG), (2006), "Saltpetre from India", A Galathea 3 Project, Report No. 6, 17 pp.

Pinnel, M.R., (1979), "Diffusion-related Behaviour of Gold in Thin Film Systems", Gold Bulletin, 12(2), pp. 62-71.


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