Ministry of Mining Industry and Geology of the Republic of Uzbekistan, Tashkent, Uzbekistan

B. T. Berdiyarov, Head of the Department for Rare and Technological Metals Development, Doctor of Technical Sciences

Uzbek-Japanese Innovation Center for Youth at Tashkent State Technical University, Tashkent, Uzbekistan
S. T. Matkarimov, Head of the Laboratory of Mining and Deep Processing of Mineral Resources

Tashkent State Technical University, Tashkent, Uzbekistan
Sh. A. Mukhametdzhanova, Associate Professor, Department for Metallurgy, Candidate of Technical Sciences, e-mail: shoira.muhamet@gmail.com
S. K. Nosirkhodzhaev, Head of the Department for Metallurgy, Candidate of Technical Sciences, Associate Professor

The article presents the results of a study of the process of roasting zinc concentrates containing iron and silicon using oxygen-enriched air, as well as the development of an optimal composition of the charge to reduce ferrite and silicate formation. Zinc ferrites and silicates are very poorly soluble in sulfuric acid solutions and largely transfer into cakes. The yield of cakes depends on the feedstock composition and, when processing medium-quality concentrate, is 40–45% of the mass of the initial charge. To study the causes that reduce the formation of ferrites and zinc silicates during the roasting process, alkali and alkaline earth metal oxides (CaO, BaO, Na₂O, K₂O), natural minerals CaCO₃, as well as wastewater from the copper concentration plant of JSC AMMC, which contain these compounds, were added to the charge. During roasting, blast enriched with oxygen up to 28% was used, which allowed to significantly increase the productivity of the fluidized bed furnace and reduce the duration from 2 to 1.5 hours. The use of lime in the composition of the charge in the amount of 12 and 15% of the charge mass contributed to the reduction of ferrite formation to 0.6%, silicate formation to 1.2%. Also, the oxidation of sulfides was studied and the degree of desulfurization was determined, which depends on the temperature and duration of roasting. With an increase in the oxygen content in the blast, it becomes possible to charge concentrate with increased humidity into the furnace, which will reduce possible costs for preliminary drying of raw materials.

1. Orlov A. K. Stages of sulfide oxidation during oxidative roasting of zinc concentrates. Tsvetnye Metally. 2003. No. 10. pp. 25–26.
2. Alkatsev V. M., Rutkovskiy A. L., Makoeva A. K. Study of the process of roasting zinc concentrates in a fluidized bed by the method of mathematical modeling. Ipolytech Jourmal. 2022. Vol. 26, No. 4. pp. 669–676. DOI: 10.21285/1814-3520-2022-4-669-676
3. Liu F. L., Jin Z. M., Wang L. S. Kinetics of the formation reaction of Zn2SiO4 during the firing of high-silicon sphalerite concentrate. Chin. J. Nonferr. Met. 2001. Vol. 11, No. 3. pp. 514–517.
4. Elfimova L. G., Lobanov V. G. Processing of sulphide concentrates and industrial products using the roasting-leaching scheme. Modern technologies for production of non-ferrous metals: Proceedings of the International Scientific Conference dedicated to the 80^th anniversary of S. S. Naboychenko, Yekaterinburg, March 24–25, 2022. Yekaterinburg : Izdatelstvo Uralskogo universiteta, 2022. pp. 291–298.
5. Akhtamov F. E., Isaeva S. S., Buronov M. K. Study of the possibility of using water vapor in the complex processing of zinc cake. Journal of Advance in Engineering technology. 2021. Vol. 1(3). pp. 35–38. DOI: 10.24412/2181-1431-2021-1-35-38
6. Junwei Han, Wei Liu, Wenqing Qin, Bing Peng et al. Recovery of zinc and iron from high iron-bearing zinc calcine by selective reduction roasting. Journal of Industrial and Engineering Chemistry. 2015. Vol. 22. pp. 272–279. DOI: 10.1016/j.jiec.2014.07.020
7. Marchenko N. V., Vershinina E. P., Gildebrandt E. M. Metallurgy of heavy non-ferrous metals [Electronic resource]: electronic textbook. Electronic data (6 Mb). Krasnoyarsk : IPK SFU, 2009.
8. Yong Ke, Ning Peng, Ke Xue, Xiaobo Min et al. Sulfidation behavior and mechanism of zinc silicate roasted with pyrite. Applied Surface Science. 2018. Vol. 435. pp. 1011–1019. DOI: 10.1016/j.apsusc.2017.11.202
9. Xu H., Qian Y., Zhou Q., Wei C. et al. Leaching of willemite concentrate in sulfuric acid solution at high temperature. Sustainability. 2023. Vol. 15, Iss. 1. 161. DOI: 10.3390/su15010161
10. Berdiyarov B. T., Yusupkhodjayev A. A., Khasanov A. S., Akramov J. R. Improvement of technology of heat treatment of the zinc concentrate for the purpose of increase in complexity of use of raw materials. International Journal of Advanced Research in Science, Engineering and Technology. 2019. Vol. 6, Iss. 2. pp. 8157–8163.
11. Yakubov M. M., Abdukadyrov A. A., Mukhametdzhanova Sh. A., Yokubov O. M. Involvement in the production of man-made formations at the Almalyk MMC JSC enterprise. Non-ferrous metals. 2022. No. 5. pp. 36–41.
12. Yusupkhodjayev A. A., Berdiyarov B. T., Nosirkhujayev S. Q. U. Technology of deep processing of copper slags by method of active thermal gravity. International Journal of Advanced Science and Technology. 2020. Vol. 29, No. 3. pp. 5633–5639.
13. Matkarimov S. T., Yusupkhodjaev A. A., Khojiev Sh. T., Berdiyarov B. T., Matkarimov Z. T. Technology for the complex recycling slags of copper production. Journal of Critical Reviews. 2020. Vol. 7, Iss. 5. pp. 214–220. DOI: 10.31838/jcr.07.05.38
14. Metsörinta M.-L., Taskinen P., Nyberg I., Ovo E. Mechanisms of fluidized bed roasting of contaminated zinc concentrate. Tsvetnye Metally. 2005. No. 5-6. pp. 92–99.