Proof-of-Concept Testing of a Gold Recovery Process Using Magnetic Activated Carbon

72321-The processing rate in gold extraction applications is limited by current production methods. Pulverized activated carbon could be used to improve reaction kinetics, reduce energy consumption, and minimize the waste generated per unit of gold produced; however, this carbon cannot be separated from the ore. This project will develop technology for rendering the powdered carbon magnetic so that it can be separated from the host ore after adsorption of the dissolved gold. The approach will improve gold recovery from difficult ore deposits resulting in increased mine life and extraction efficiency, as well as reducing the energy consumed and environmental impact per ton of ore mined. In Phase I, samples of magnetic activated carbon were prepared using various procedures and raw materials. The carbon samples were evaluated for gold adsorption and magnetic characteristics. Results indicate that current standards for gold recovery can be met or exceeded with improvements in both processing rate and gold recovery. Phase II will demonstrate the magnetic carbon process on a continuous basis in an operating mining environment; on-site testing is critical to determine whether the plant operating environment and/or process variances will influence the results. All critical design parameters will be measured, in order to in engineer a Phase III demonstration facility. Commercial Applications and Other Benefits as described by awardee: The primary application for this technology is in gold mining. Other uses include improved purification of drinking water, treatment of contaminated ground water, and mercury removal from power plant and waste incineration flue gas. All applications offer the benefit of improved management of natural resources and reduced environmental impact. This technology will also add to the manufacturing base for domestic activated carbon producers to help offset the recent increase in foreign competition.