Ural Federal University named after the first President of Russia B. N. Yeltsin, Scientific Laboratory of Advanced Technologies for Complex Processing of Mineral and Technogenic Raw Materials of Nonferrous and Ferrous Metals, Yekaterinburg, Russia:

K. A. Karimov, Senior Researcher, Candidate of Technical Sciences, e-mail: kirill_karimov07@mail.ru
O. A. Dizer, Researcher, Candidate of Technical Sciences

D. A. Rogozhnikov, Head of Laboratory, Doctor of Technical Sciences

Research Center “Hydrometallurgy”, St. Petersburg, Russia:
E. A. Kuzas, Head of Research and Technology Department, Candidate of Technical Sciences

The results of studies on the precipitation of arsenic sulfide (III) from multicomponent solutions of nitric acid leaching of refractory sulfide raw materials of non-ferrous metals containing iron (III) ions, using sodium hydrosulfide as a precipitant, are presented. The effect of temperature, pH solution, NaHS consumption, and seed (arsenic sulfide As₂S₃) on this process was studied. The highest degree of precipitation of arsenic sulfide (III) (95–99%) from nitric acid solutions containing iron (III) ions without seeding occurs at pH from 1.8 to 2.0 and the NaHS/As molar ratio = 2.8. An increase in temperature leads to a significant decrease in the degree of precipitation of arsenic sulfide (III). With an increase in temperature from 25 to 60 °C, the degree of arsenic transition to the precipitate decreases almost by half for the entire studied range of pH = 1–2. This is due to an increase in the degree of oxidation of the sulfide ion by iron (III) ions to elemental sulfur, which is also confirmed by a decrease in the Fe_tot/Fe²⁺ ratio in solution to 1.05–1.01. The introduction of the seed significantly improves the precipitation of arsenic sulfide (III). Increasing the seed consumption from 0 to 34 g/dm3 solution increases the degree of arsenic transfer to the precipitate from 36.2 to 98.1% at pH = 1. The addition of the seed probably accelerates the crystallization of arsenic sulfide (III) by increasing the number of crystallization centers, as a result of which the As₂S3 precipitation rate becomes higher, and the rate of oxidation of sulfide ions to elemental sulfur by iron (III) ions changes insignificantly, which, in turn, enables to reduce the molar flow rate of NaHS/As to 2.25 and to obtain the precipitate with a lower amount of elemental sulfur and a high content of arsenic.

The study was carried out within the framework of the Russian Science Foundation project No. 22-79-10290. Analytical studies were carried out with the financial support of the State Task of the Russian Federation under Grant No. 075-03-2021-051/5 (FEUZ-2021-0017).

1. Liu X., Li Q., Zhang Y., Jiang T., Yang Yo. et al. Improving gold recovery from a refractory ore via Na2SO4 assisted roasting and alkaline Na₂S leaching. Hydrometallurgy. 2019. Vol. 185. pp. 133–141.
2. Zaytsev P. V., Fomenko I. V., Chugaev L. V., Shneerson Ya. М. Pressure oxidation of double refractory raw materials in the presence of limestone. Tsvetnye Metally. 2015. No. 8. pp. 41–49.
3. Miller P., Brown A. Bacterial oxidation of refractory gold concentrates. Developments in Mineral Processing Advances in Gold Ore Processing. Elsevier, 2005. pp. 371–402.
4. Hourn M. Refractory leaching solutions. Australian Mining. 2009. Vol. 101, No. 2. p. 20.
5. LEACHOX is a process for processing refractory gold ores and concentrates. Review. GOLD MINING. Gold mining, technologies, equipment. Available at: https://zolotodb.ru/article/12208 (accessed: 07.06.2023).
6. Johnson G., Corrans I., Angove J. The Activox process for refractory gold ores. Randol Gold Forum – Beaver Creek‘93. 7–9 September, 1993. Proceedings. pp. 183–189.
7. Rogozhnikov D. А., Dizer О. А., Karimov К. А., Shoppert А. А., Kuzas Е. А. Nitric acid processing of sulfide raw materials of non-ferrous metals: monograph. Edited by S. S. Naboychenko. Yekaterinburg : Izdatelstvo UMTs UPI, 2020. 242 p.
8. Moon D. H., Dermatas D., Menounou N. Arsenic immobilization by calcium – arsenic precipitates in lime treated soils. Science of The Total Environment. 2004. Vol. 330, No. 1. pp. 171–185.
9. Zhu Y. N., Zhang X. H., Xie Q. L., Wang D. Q., Cheng G. W. Solubility and Stability of Calcium Arsenates at 25 ^oC. Water Air Soil Pollut. 2006. Vol. 169, No. 1. pp. 221–238.
10. Riveros P. A., Dutrizac J. E., Spencer P. Arsenic disposal practices in the metallurgical industry. Canadian Metallurgical Quarterly. 2001. Vol. 40, No. 4. pp. 395–420.
11. Grebneva A. A., Subbotina I. L., Timofeev K. L., Maltsev G. I. Development of technology of arsenic removal from acidic waste solutions in the form of arsenic trisulfide. KnE Materials Science. 2020. pp. 209–213.
12. Xu H., Min X., Wang Y., Ke Y., Yao L. et al. Stabilization of arsenic sulfide sludge by hydrothermal treatment. Hydrometallurgy. 2020. Vol. 191. 105229.
13. Ostermeyer P., Bonin L., Folens K., Verbruggen F., García-Timermans C. et al. Effect of speciation and composition on the kinetics and precipitation of arsenic sulfide from industrial metallurgical wastewater. Journal of Hazardous Materials. 2021. Vol. 409. 124418.
14. Hu B., Yang T.-Z., Liu W.-F., Zhang D.-C., Chen L. Removal of arsenic from acid wastewater via sulfide precipitation and its hydrothermal mineralization stabilization. Transactions of Nonferrous Metals Society of China. 2019. Vol. 29. pp. 2411–2421.
15. Rogozhnikov D. А., Zakharian S. V., Dizer О. А., Karimov К. А. Nitric acid leaching of copper-bearing arsenic sulfide concentrate of Akzhal. Tsvetnye Metally. 2020. No. 8. pp. 11–17.
16. Rogozhnikov D. A., Shoppert A. A., Dizer O. A., Karimov K. A., Rusalev R. E. Leaching kinetics of sulfides from refractory gold concentrates by nitric acid. Metals. 2019. No. 4. 465.
17. Stephen H., Stephen T. Solubilities of inorganic and organic compounds. Vol. 1: Binary Systems. Part. 1. Pergamon Press: Oxford, NY, USA. 1963. 975 p.
18. Swash P. M., Monhemius A. J. Synthesis, characterization and solubility testing of solids in the Ca – Fe – AsO₄ system. Proceedings of the Sudbury’95 on Mining and the Environment CANMET, Sudbury, May 28 – 1 June 1995, Canada. pp. 17–28.
19. Karimov K. A., Rogozhnikov D. A., Kuzas E. A., Shoppert A. A. Leaching kinetics of arsenic sulfide-containing materials by copper sulfate solution. Metals. 2020. Vol 10, Iss. 7. DOI: 10.3390/met10010007
20. Floroiu R. M., Davis A. P., Torrents A. Kinetics and Mechanism of As₂S₃(am) Dissolution under N2. Environ. Sci. Technol. 2004. Vol. 38, No. 4. pp. 1031–1037.
21. Zhang G., Chao X., Guo P., Cao J., Yang C. Catalytic effect of Ag+ on arsenic bioleaching from orpiment (As2S3) in batch tests with Acidithiobacillus ferrooxidans and Sulfobacillus sibiricus. Journal of Hazardous Materials. 2015. Vol. 283. pp. 117–122.
22. Rochette E. A., Bostick B. C., Li G., Fendorf S. Kinetics of arsenate reduction by dissolved sulfide. Environ. Sci. Technol. 2000. Vol. 34, No. 22. pp. 4714–4720.