Development of a radiotracer technique to evaluate gold recovery by gravity concentrators

CIM Bulletin, Vol. 79, No. 895, 1986

DANIEL E. WALSH and P.O. RAO, University of Alaska, Fairbanks, Alaska

Gravity concentrators are evaluated either in closed or open circuit. The process developed by MIRL employs the use of neutron activated gold (>9SAu) and radiation detection circuits which monitor the concentrator's product pulp streams. Concentrator recovery is determined from the ratio of the number of gold particles detected as passing into the concentrate to the total number of gold particles detected over all monitored pulp streams. This system eliminates the experimental errors introduced by sampling, sample reduction, and assaying and allows recovery to be evaluated for gold particles of specific sizes, shapes, and flatness. In addition to allowing for a more accurate and detailed recovery analysis, this process significantly reduces the time and cost required for unit evaluation when compared to other gold recovery analysis procedures. This system enjoys its greatest utility where a large number of tests are to be run in order to evaluate a concentrator over a variety of operational settings, i.e. factorial designs, and allows accurate testing of concentrators operated in closed circuit systems.
Keywords: Mineral processing, Gold recovery, Gravity concentration, Radiotracer, Concentrator recovery, Radiation, Neutron capture reaction.