VNIIHT, Moscow, Russia:
E. V. Ovcharenko, Senior Researcher, e-mail: molchanovatv@vniiht.ru
T. V. Molchanova, Head of Laboratory; e-mail: molchanovatv@vniiht.ru
K. M. Smirnov, Head of Department; e-mail: smirnov@vniiht.ru
О. К. Krylova, Deputy Head of Department, Head of Laboratory, e-mail: lab-v-1@vniiht.ru

This paper describes the results of the study that looked at sorption recovery of gold from low-grade solutions which simulate the bypass solutions of gold tailings. The basic process regularities were examined of the gold sorption and desorption in dynamic conditions when using the weak-base macroporous anion-exchange resin Purogold S992 versus the AM-2B anion-exchange resin of mixed basicity and the activated carbon LC-0612. Recovery of the saturated anion-exchange resin Purogold S992 followed a standard process, i.e. 20 g/dm³ NaCN and 5 g/dm³ NaOH at 60 ^oC in a static mode. The concentration of gold in the eluate was 35 mg/dm3, the residual gold concentration was 0.07 mg/g. After resaturation the anion-exchange resin concentration rose to 87 mg/g. When processing the Savkino deposit ores by heap leaching, the passing of gold in solution during 21 days was 87–88%. In the following sorption of gold with activated carbon the recovery was 98.8%, and the desorption of gold from saturated carbon into cyano-basic eluates was as high as 98.0%. The paper describes a design of a sorption column for recovery of gold from low-grade solutions. A treatment method is proposed for removing mercury from the product of heap leaching of the gold ores from the Savkino deposit. The method is based on calcium sulphide deposition, which uses a mixture of calcium oxide and sodium sulphide. The purification efficiency reaches 99.96%. A cold desorption process was tested as a process that helps remove mercury from the gold containing activated carbon. The mercury desorption degree reached was 96.7%. This method helps streamline the following gold desorption process and the production of finished product.

1. Aleksandrova T. N., Lipina L. N. Mining waste as potential gold mining reserve. Gornyy informatsionno-analiticheskiy byulleten. 2015. No. 6. pp. 202–205.
2. The prospects of gold sorption with anion resins and activated carbon in the processing of low-grade gold ores – In-situ and heap leaching of uranium, gold and other metals. Ed. by M. I. Fazlullin: 2 volumes. Vol. 2: Gold. Moscow : “Ore and Metals” Publishing House, 2005. 328 p.
3. Strukov K. I., Plotnikov S. N., Nikolaev Yu. L., Plotnikova I. E. Introduction of gold heap leaching technology in the mines Kurosan, Svetlinskiy and Bereznyakovskiy. Tsvetnye Metally. 2017. No. 9. pp. 46–52.
4. Petersen J. Heap leaching as a key technology for recovery of values from lowgrade ores – a brief overview. Hydrometallurgy. 2015. Vol. 165. pp. 206–212.
5. Manning T., Kappes D. W. Heap Leaching of Gold and Silver Ores. Gold Ore Processing: Project Development and Operations. Second ed. Amsterdam : Elsevier, 2016. pp. 413–428.
6. Farysheva M. V. The geology of the Savkino deposit (Transbaikal Territory). Vestnik RUDN. Seriya Inzhenernye issledovaniya. 2015. No. 4. pp. 125–128.
7. Gladyshev V. P., Levitskaya S. A., Filippova A. M. Analytical chemistry of mercury. Moscow : Nauka, 1974. 176 p.
8. McDougall G. J., Hancock R. D., Nicol M. J., Wellington O. L., Copperthwaite R. G. The mechanism of the adsorption of gold cyanide on activated carbon. Journal of the South African Institute of Mining and Metallurgy. 1980. Vol. 80, No. 9. pp. 344–356.
9. Fleming C. A., Nicol M. J. The absorption of gold cyanide onto activated carbon. III. Factors influencing the rate of loading and the equilibrium capacity. Journal of the South African Institute of Mining and Metallurgy. 1984. Vol. 84, No. 4. pp. 85–93.
10. Dobroskokin V. V., Ovcharenko E. V., Akimova I. D. Method for gold extraction from cyanide solutions with dissolved mercury contained in them. Patent RF, No. 2460814. Published: 10.09.2012. Bulletin No. 25.
11. Dobroskokin V. V., Ovcharenko E. V., Akimova I. D. Method of gold extraction from mercury-containing cyanic solutions. Patent RF, No. 2458160. Published: 10.08.2012. Bulletin No. 22.
12. Melnikov S. M. Metallurgy of mercury. Moscow : Metallurgiya, 1971. 472 p.
13. Okang Odumo B., Carbonell G., Angeyo H. K., Patel J. P., Torrijos M., Rodrigues Martin J. A. Impact of gold mining associates with mercury contamination in soil biota sediments and tailings in Kenia. Environmental Science and Pollution Research. 2014. Vol. 21, No. 21. pp. 426–435.
14. Kyle J. H., Brewer P. L., Bunney K. G., Pleysier R. Review of trace toxic elements (Pb, Cd, Hg, As, Sb, Bi, Se, Te) and their deportment in gold processing: Part II: Deportment in gold ore processing by cyanidation. Hydrometallurgy. 2012. Vol. 111–112. pp. 10–21.
15. Ismagilov R. I., Ovcharenko E. V., Tolkachev V. A. Method to process gold-containing ores with mercury admixture. Patent RF, No. 2497963. Published: 10.11.2013. Bulletin No. 31.
16. Smirnov V. V., Volkov V. P., Mikhin O. D., Nikitin N. V., Meshcheryakov N. M. Testing of a new generation anion-exchange resin in gold sorption recirculation cycles. Tsvetnye Metally. 2005. No. 1. pp. 49–52.
17. Volkov V. P. The sorption processes at running sites. Moscow : “Ore and Metals“ Publishing House, 2014. 159 p.