Selection of a leaching system for the extraction of gold from the ore of the Byn’govskoye deposit

A theoretical substantiation of an environmentally friendly technology for extracting gold from mineral raw materials is presented. In terms of an alternative to conventional cyanide, the authors propose chlorine-bearing derivatives of organic isocyanuric acid (C₃H₃N₃O₃). In the studied process, this reagent combines the roles of a long-acting oxidant and complexing agent due to the resulting Cl^– ion. For experimental purposes, the rotating disc technique was applied. Experimental results were evaluated by measuring the concentration of gold in solutions using the atomic adsorption method. The theoretical characteristics of gold dissolution using the proposed reagent were studied. In order to evaluate the applicability of the revealed regularities for practical purposes, comparative indicators for leaching gold from the ore of the Byn’govskoye deposit (Sverdlovsk Oblast) using the proposed reagent, cyanide and CYCAD cyanide substitute (China) were evaluated. The dependence of the gold disc dissolution rate on temperature, as well as leaching reagent and hydrochloric acid concentrations, were studied. In disc sample experiments, the exponential dependence of the dissolution rate on the concentration of the studied reagent was established. In this case, the maximum intensity of the process is achieved at a concentration higher than 50 g/dm³. The optimum acidity level comprises 0.3–0.4 g ion/dm³ of hydrochloric acid. Despite an increase in temperature being shown to accelerate the dissolution process, this appears to be technologically unjustified. Under optimal conditions, the gold disc dissolution rate reaches 0.5•10^-3 g ion/(cm²•min), which is approximately one hundred times higher than during the dissolution by the cyanic solutions in conventional modes. Close gold extraction values were achieved in the solutions of cyanides and chlorine-bearing derivatives of isocyanuric acid during the leaching of gold from the ore under the comparable conditions. For CYCAD solutions, the same indicator is two times lower. The results of the performed studies demonstrate the high dissolution rate of gold using the proposed reagent along with the technological possibility of leaching gold from ores using this environmentally friendly reagent.

1. Dmitrienko V. P., Dmitrienko I. V., Makaseev Yu. N., Si-dorov M. E. Thiourea leaching of gold from gravity concentrate. Zoloto i tekhnologii. 2019;1:82-85. (In Russ.).

2. Whitehead J. A., Zhang J., Cluskey A., Lawrance G. A. Comparative leaching of a sulfidic gold ore in ionic liquid and aqueous acid with thiourea and halides using Fe(III) or HSO5− oxidant. Hydrometallurgy. 2009;98(3-4):276-280. https://doi.org/10.1016/j.hydromet.2009.05.012.

3. Kholov K. I., Sharifboev N. T., Samikhov S. R., Dzhurakulov S. R. Gold leaching by various solutions, cyanide substitutes and their future prospects. Journal of Siberian Federal University. Engineering & Technologies. 2021;14(4):433-447. https://doi.org/10.17516/1999-494X-0324.

4. Syed S. Recovery of gold from secondary sources – a review. Hydrometallurgy. 2012;115-116:30-51. http://dx.doi.org/10.1016/j.hydromet.2011.12.012.

5. Grosse A. C., Dicinoski G. W., Shaw M. J., Haddad P. R. Leaching and recovery of gold using ammoniacal thiosulfate leach liquors (a review). Hydrometallurgy. 2003;69(1-3):1-21. https://doi.org/10.1016/S0304-386X(02)00169-X.

6. Gökelma M., Birich A., Stopic S., Friedrich B. A Review on alternative gold recovery reagents to cyanide. Journal of Materials Science and Chemical Engineering. 2016;4(8):8-17. https://doi.org/10.4236/msce.2016.48002.

7. Tein I., Ziyadanogullari R. The effect of sulfurization process on flotation of copper ore containing gold and silver. Journal of Minerals and Materials Characterization and Engineering. 2008;7(3):193-202. http://dx.doi.org/10.4236/jmmce.2008.73015.

8. Hodouin D., Makni S. Real-time reconciliation of mineral processing plant data using bilinear material balance equations coupled to empirical dynamic models. International Journal of Mineral Processing. 1996;48(3-4):245-264. https://doi.org/10.1016/S0301-7516(96)00025-7.

9. Shiryaeva V. V. Development of a technological regime for gold recovery from complex gold-uranium ores by heap leaching using rhodanide solutions. Gornyj informacionno-analiticheskij byulleten' = Mining informational and Analytical Bulletin. 2012;7:403-412. (In Russ.).

10. Baghalha M. Leaching of base gold-bearing ore with chloride-hypochlorite solutions. International Journal of Mineral Processing. 2007;82(4):178-186. https://doi.org/10.1016/j.minpro.2006.09.001.

11. Olteanu A. F., Dobre T., Panturu E., Radu A. D., Akcil A. Experimental process analysis and mathematical modeling for selective gold leaching from slag through wet chlorination. Hydrometallurgy. 2014;144-145:170-185. https://doi.org/10.1016/j.hydromet.2014.02.011.

12. Guo Xue-Yi, Liu Zuo-Wei, Tian Qing-Hua, Li Dong, Zhang Lei. Gold extraction from Carlin-type concentrate by a novel environmentally friendly lixiviant. Hydrometallurgy. 2022;211:105884.https://doi.org/10.1016/j.hy-dromet.2022.105884.

13. Yannopoulos J. C. The extractive metallurgy of gold. New York: Van Nostrand Reinhold; 1991, 273 р. https://doi.org/10.1007/978-1-4684-8425-0.

14. Neto I. F. F., Soares H. M. V. M. Simple and near-zero-waste processing for recycling gold at a high purity level from waste printed circuit boards. Waste Management. 2021;135:90-97. https://doi.org/10.1016/j.was-man.2021.08.025.

15. Ahtiainena R., Lundström M. Cyanide-free gold leaching in exceptionally mild chloride solutions. Journal of Cleaner Production. 2019;234:9-17. https://doi.org/10.1016/j.jclepro.2019.06.197.

16. Hasab M. G., Rashchi F. Chloride–hypochlorite leaching and hydrochloric acid washing in multi-stages for ex-traction of gold from a refractory concentrate. Hydrometal-lurgy. 2014;142:56-59. https://doi.org/10.1016/j.hy-dromet.2013.11.015.

17. Barani K., Kogani Y., Nazarian F. Leaching of complex gold ore using a cyanide-glycine solution. Minerals Engineering. 2022;180:107475. https://doi.org/10.1016/j.mineng.2022.107475.

18. Samikhov S. R. Studying kinetic of gold and silver cyanidation from the Mosarif deposit ores. Nauka i innovaciya = Science and Innovation. 2014;1:88-92. (In Russ.).

19. Khabibulina R. E., Lobanov V. G. Environmentally friendly technology of gold leaching from anthropogenic raw materials. In: Aktual'nye problemy razvitiya tekhnich-eskih nauk: sbornik statej uchastnikov XXIV Oblastnogo konkursa nauchno-issledovatel'skih rabot “Nauchnyj Olimp” po napravleniyu “Tekhnicheskie nauki” = Topical problems of engineering sciences development: collected articles of the participants of the 24th Regional competition of research works "Scientific Olympus" in the direction of "Engineering Sciences". Ekaterinburg: Ural Federal Univer-sity named after the First President of Russia B.N. Yeltsin; 2021, р. 31-35. (In Russ.).

20. Khabibulina R. E., Lobanov V. G., Kolmachihina O. B., Konovalov M. V., Druzhinin D. I. Environmentally friendly extraction of gold from concentrates. Sovremennye tekhnologii proizvodstva cvetnyh metallov: materialy Mezhdunarodnoj nauchnoj konferencii, posvyashchennoj 80-letiyu S. S. Nabojchenko = Modern production technologies for non-ferrous metals: materials of the International scientific conference dedicated to the 80th anniversary of S. S. Naboychenko (24 March 2022, Ekaterinburg. Ekaterinburg: Ural Federal University named after the First Pres-ident of Russia B.N. Yeltsin; 2022, р. 192-196. (In Russ.).