Title: Investigations for the low gold recovery at Mpanda Mineral Field in Western Tanzania

Authors: Jeremiah Mosingo; Alphonce Wikedzi

Addresses: Department of Mining and Mineral Processing Engineering, College of Earth Sciences and Engineering, The University of Dodoma, P.O. Box 259 Dodoma, Tanzania ' Department of Mining and Mineral Processing Engineering, School of Mines and Geosciences, University of Dar es Salaam, P.O. Box 35131, Dar es Salaam, Tanzania

Abstract: This study investigated the main causes of low gold recovery obtained at the Mpanda Mineral Field (MMF) and recommended a potential treatment process. The ore samples were characterized to establish chemical, mineralogy, and total organic carbon (TOC) information. It was found that the main causes of low gold recovery are the presence of copper minerals (covellite, cuprite, and chalcocite), metallic copper (>0.5% Cu), and carbonaceous materials indicated by the TOC contents (>2.5%). The chemical analysis showed that the investigated ores contained greater than 2.9 ppm gold. Box-Behnken experimental design was adopted to investigate the effects of the experimental factors on gold recovery. The maximum gold recovery of 89.4% was achieved using the following parameter levels: 0.50 M Na₂S₂O₃, 0.94 M NH₃, and 0.06 M CuSO₄. Generally, the problem faced at MMF is caused by the reactive copper minerals and carbonaceous materials. Thiosulphate leaching is recommended to be the treatment process.

Keywords: vat leaching; thiosulphate leaching; reactive copper minerals; carbonaceous materials; total organic carbon; Box-Behnken experimental design; Mpanda Mineral Field; MMF; Tanzania; gold; copper-gold ores.

DOI: 10.1504/IJMME.2023.137370

International Journal of Mining and Mineral Engineering, 2023 Vol.14 No.4, pp.365 - 379

Received: 23 Jan 2023
Accepted: 06 Nov 2023
Published online: 14 Mar 2024 *

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