Kazmekhanobr's technologies in the field of processing of low-grade gold-bearing ores and technogenic raw materials

Abstract

The Republic of Kazakhstan has been increasing gold production annually for the last 10–15 years. According to the results of 2019, Kazakhstan ranks 13th in the world in terms of gold production (77 tons), in terms of reserves — 16th in the world (377.5 tons). The article presents information about the innovative developments of Kazmekhanobr in the field of processing of poor goldbearing ores and man-made raw materials. Information on implemented technologies and projects in Kazakhstan for recent years is given. Kazmekhanobr’s deve lopments cover the whole complex of technological stages of processing of poor gold-bearing ores and man-made raw materials by heap leaching technology: ore preparation, leaching process, sor ption extraction of gold from productive solutions, desorption of gold from saturated sorbents and electrolytic extraction of gold from rich eluates. In particular, the company for the first time in Kazakhstan in 1998 developed and implemented pre-pelleting of ore and laying it in a pile leaching stack using a stacker at the mines “Suzdal”, “Mukur”, “Mizek”, “Komarovsky”, etc. It was also developed the highly efficient innovative technology of gold heap leaching from poor gold-bearing ores, complex gold-copper ores and technogenic wastes, which is characterized by low consumption of water and reagents and accordingly low negative load on the environment at the mines “Zhanan”, “Mukur”, “Miyali” “Balazhal”, “Aksu”,“Bestyube”,“Uzboy”, etc. Patents were obtained and a three-stage cascade scheme of sorption extraction of gold by ion exchange resin, original design of sorption columns and binding of columns were introduced, which allowed to maximize the heap leaching process and increase its efficiency, minimize processes of resin pumping processes and, accordingly, the mechanical impact on them, will increase saturation of the resin with gold and reduce the turnover of gold with working solutions at the Zhaltyrbulak, Uzboy, Vasilyevskoye deposits. Innovative processes of highefficiency technology of gold desorption and ion exchange resin regeneration, electrolytic extraction of gold from commodity regenerates have been introduced, in which the duration of gold desorption and resin regeneration together with gold electrolysis does not exceed 18–24 h. According to the projects developed by Kazmekhanobr with the use of innovative technologies, plants for the production of Dore alloy in Ust-Kamenogorsk, Semey and Stepnogorsk, Makmala (Kyrgyzstan) and the Asi gold mining plant (China) were built and successfully operate.