Size fraction assaying of gold bearing rocks (for gold extraction) by instrumental neutron activation analysis

Abstract

A novel method has been developed for processing and extraction of gold from gold bearing rocks for use by small-scale gold miners in Ghana. The methodology involved crushing of gold bearing hard rocks to fine particles to form a composite sample and screening at a range of sizes. Gold distribution in the composite sample was determined as a function of particle size by using Instrumental Neutron Activation Analysis. The concentrations of gold for the corresponding particle sizes were 16.4 ± 0.17 mg/kg for sizes < 63 μm; 161 0.75 mg/kg for 63 - 125 μm, 0.53 ± 0.03 mg/kg for 125 - 250 μm, 4.66 ± 0.07 mg/kg for 250 - 355 μm, 1.55 ± 0.06 mg/kg for 355 - 425 μm, 0.80 ± 0.008 mg/kg for 425-1000 μm, and 1.27 ± 0.05 mg/kg for 1000 - 2000 μm. The average gold content in a 7.127 kg compo-site sample based on particle size was found to be 3.80 mg/kg.

Journal of Applied Science and Technology Vol. 10(1&2) 2005: 91-96