Application of High-Power Electromagnetic Pulses to Desintegration of Gold-Containing Mineral Complexes

Abstract

The application of High-Power Electromagnetic Pulses (HPEMP) irradiation in dressing of resistant gold- containing ores appears attractive as this technique provides for a significant increase in precious metal recovery (30-80% for gold and 20-50% for silver), therewith helping reduce both energy consumption and the cost of products. This study deals with plausible mechanisms of disintegration of mineral particles under the action of nanosecond HPEMP with high electric field strength ii~107 V/m. Experimental data are presented to confirm the formation of breakdown channels and selective disintegration of mineral complexes as a result of pulse irradiation, which makes for efficient access of lixiviant solutions to precious metal grains and enhanced precious metal recovery into lixivia during leaching. We studied the influence of HPEMP on the technological properties of particles of refractory gold- and silver-containing ores and beneficiation products from Russian deposits. Preliminary processing of gravity concentrate of one deposit ore with a series of HPEMP resulted in significant increase of gold and silver extraction into lixivia during the cyanidation stage, with gold recovery increased by -31% (from 51.2% in a blank test to 82.3% after irradiation) and silver recovery increased by 47% (from 21.8% to 68.8%). Gold recovery from stale gold-containing dressing tailings of the two integrated mining-and-dressing works increased after pulses-irradiation from 8-12% to 80-90%.