In-Processing Plant Recovery of Gold from Waste Activated Carbon Using a Novel Reactor Designed at the University of Mines and Technology, Tarkwa, Ghana

W. K. Buah, G. Quartey, K. O. Akyaw, E. Abotar

Abstract


A novel reactor for plant-site preparation/ashing of gold loaded Waste Activated Carbon (WAC) for recovery of gold by cyanidation has been designed. Test Trials on combustion of various samples of WAC were carried out using the reactor and assessment of leachability of the oxidized WAC obtained from the reactor was also carried out. Combustion of the carbon fractions of WAC from various companies produced ash with gold enrichment ratio of 8.5 - 9.6 (>730%) in relation to the carbon fraction feed. Gold recoveries from the ash products are about 96% @ 1000 ppm cyanide and 64% @ 200 ppm cyanide. It is proposed that plant-site treatment of WAC shall comprise separation of the carbon fraction from the WAC, ashing of the carbon fraction, leaching at 1000 ppm and sending the leach solution for electrowinning and smelting to obtain bullion. This reactor can be integrated into the operations of gold processing plants to treat WAC for in-plant gold recovery.  This technology has the potential to generate US$57,153.11 from a tonne of ashed WAC at operational cost of about US$9,000.00. Material cost of fabrication of the reactor is about US$10,000.00.


Keywords


Waste Activated Carbon (WAC), Combustion, Gold Recovery.

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References


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