Abstract
The feasibility of a process involving the use of activated carbon in a multistage column (NIMCIX contactor) for the recovery of gold from unclarified pregnant solutions was investigated on pilot-plant scale. It was found that satisfactory extractions, corresponding to a recovery of 99.6 percent, can be achieved with an average gold concentration of 0.0077 p.p.m. in the barren solutions from a feed averaging 1.89 p.p.m. The results show that excessive loading of CaCO3 can be prevented by lowering of the pH of the feed to about 7.6. This obviates the need for the carbon to be treated with hydrochloric acid. The gold was eluted from the carbon by the Zadra procedure. The operating conditions of the elution and electrowinning circuits are reported, and the elution of the gold and other metals is discussed. The reactivation of the carbon, which was carried out in a vibrating-deck kiln, is described, and the effects of this reactivation on the activity of the carbon and its microstructure are also discussed. The consumption of reagents in the adsorption and elution circuits is presented in sufficient detail to allow the potential of the activated-carbon process as an alternative to the Merrill-Crowe process for the treatment of high-grade solutions to be evaluated. In addition, the results of parallel small-scale investigations on the effect of pH on the loading of CaCO3, gold, and other metals on activated carbon are presented and discussed briefly.
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References
A.K. Haines, “The Development of Continuous Fluidized-bed Ion Exchange in South Africa, and Its Use in the Recovery of Uranium,” Journal of the South African Institute of Mining and Metallurgy, 78 (12) (1978) pp. 303–315.
J.B. Zadra, A.L. Engel and H.J. Heinen, “Process for Recovering Gold and Silver from Activated Carbon by Leaching and Electrolysis,” U.S. Bureau of Mines, R.I. 4843, Feb. 1952.
R.L. Paul, A.O. Filmer and M.J. Nicol, “The Recovery of Gold from Concentrated Aurocyanide Solutions,” Hydrometallurgy: Research, Development and Plant Practice, edited by Osseo-Asare and J.D. Miller, AIME Symposium, Atlanta, 1983, pp. 689–704.
R.J. Davidson, V. Veronese and M.V. Nkosi, “The Use of Activated Carbon for the Recovery of Gold and Silver from Gold-plant Solutions,” Journal of the South African Institute of Mining and Metallurgy, 79 (5) (1979) pp. 281–297.
C.A. Fleming and M.J. Nicol, “The Absorption of Gold Cyanide onto Activated Carbon. III. Factors Influencing the Rate of Loading and the Equilibium Capacity,” Journal of the South African Institute of Mining and Metallurgy, 84 (4) (1984) pp. 85–93.
A.O. Filmer, “The Electrowinning of Gold from CIP Eluates,” Seminar on Carbon-in-Pulp Technology for the Extraction of Gold, Kalgoorlie, Australia, 1982.
A.W. Lowen, “Perspectives on Carbon Regeneration,” Chemical Engineering Progress, 69 (11) (1973) pp. 56–62.
M.J. Nicol, “Elution Theory,” (Paper presented at the SAIMM School: “Design and Operation of Plants for the Recovery of Gold by Activated Carbon,” Randburg, South Africa, 14–18 October 1985).
R.M. Mendick, “An Economic Comparison of the Carbon-in-Pulp and Merrill-Crowe Processes for Precious Metal Recovery,” Process Economics International, III (4) (1983) pp. 38–42.
P.A. Laxen, “General Introduction,” (Paper presented at the SAIMM School: “Design and Operation of Plants for the Recovery of Gold by Activated Carbon,” Randburg, South Africa, 14–18 October 1985).
B.N. Laskorin, G.I. Sadovnikova and E.I. Skityaeva, “Effect of Activated Coal Microstructure on Gold Sorption from Solutions,” Soviet Journal of Non-ferrous Metals, 7 (1973) pp. 19–21.
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A. Mehmet, W.A.M. te Riele and D.W. Boydell are currently with the Council for Mineral Technology in Randburg, South Africa.
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Mehmet, A., te Riele, W.A.M. & Boydell, D.W. Au Recovery Using an Activated Carbon Column. JOM 38, 23–28 (1986). https://doi.org/10.1007/BF03257811
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DOI: https://doi.org/10.1007/BF03257811