Abstract

LOUARRAT, M. et al. Optimization of conditions for the preparation of activated carbon from olive stones for application in gold recovery. J. S. Afr. Inst. Min. Metall. [online]. 2019, vol.119, n.3, pp.297-306. ISSN 2411-9717.  http://dx.doi.org/10.17159/2411-9717/2019/v119n3a9.

The purpose of this study is to prepare a new activated carbon from olive stones for use in gold recovery by carbon-in-leach (CIL) and carbon-in-pulp (CIP). The preparation method chosen was physical activation using steam. The effect of four process parameters: the residence time for carbonization, the activation temperature, the residence time for activation, and steam flow, were studied by the mean of response surface method (RSM) in order to optimize the yield, iodine index, and attrition characteristics. These two last responses were used as primary indicators of gold recovery capacity and mechanical strength. The results obtained show that optimal activated carbon can be prepared under the following conditions: a carbonization time of 157 minutes, activation at 921°C for 53 minutes, and a water vapour flow of 0.18 mL/min. This optimum carbon has an iodine value greater than 1100 mg/g and an attrition index in the order of 0.74%. These values reflect the quality of the precursor (olive stones) as a raw material for the development of an effective new activated carbon for the gold mining industry.

Keywords : olive stones; activated carbon; response surface method (RSM); physical activation; gold recovery.

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