Mineral processing of gold
Rudashevsky V. N., Rudashevsky N. S., Antonov A. V., Nabiullin F. M., Pastukhov D. M.
Zapiski RMO (Proceedings of the Russian Mineralogical Society). 2017. V. 146. N 1. P. 103-125
The 3D mineralogical-geochemical technology is applied for research of precious metal bearing matrix rocks, ores and their process products. This technology implies study of primary and modified process products using highly sensitive modern physical-chemical methods of analysis of pre-sized materials after its stage-by-stage crushing, or electric-pulse disaggregation (EPD) and gravity separation by means of hydroseparation. It is shown that this technology provides statistically representative detailed information on a phase level. The overview of different processing methods of the gold bearing ores is presented. The critical analysis of metal losses as a result of processing of Berezovsky mine ores and recovery of Au by means of tank cyanide leaching and problem solution of, so called «refractory» gold ores are provided. It is shown that the main portion of Au loss after cyanide leaching of the concentrate (2.5 ppm of Au) occurs in an unlocked gold of different coarse (0.5—0.1 mm) fractions of leaching tailings containing 8.2 to 1.3 ppm. The grain size boundary of Au concentrate should not exceed 100 microns. The separate cyanide leaching of the coarse and fine grained fractions of the flotation concentrate with additional grinding of the coarse fraction down to –50 microns will lead to decrease of Au content in the tank leaching tailings down to 0.7—0.9 ppm which corresponds to 97 % of Au recovery. The re-processing of the stored rich (2.3—2.5 ppm of Au) tank cyanide leaching tailings will generate secondary railings with less than 1 ppm of Au which corresponds to over 70 % recovery. The flowchart for re-processing of the stock-pile of tailings and update of current industrial process for recovery of additional gold from ores of Berezovsky mine are under development.
Key words: gold, 3D mineralogical-geochemical technology, hydroseparation, electric-pulse disaggregation (EPD), gold processing technologies, «refractory» gold, cyanide leaching, gold tailings.