AP23490117 – Development of technology for complex processing of pyrite concentrates to produce iron oxide pigments and ultrafine metal powders

Objective of the project – Development of a comprehensive technology for processing pyrite concentrates to produce iron oxide pigments (Fe2O3, Fe3O4), metal oxide powders (Fe2O3, Fe3O4) and ferrites based on them of the composition NiFe2O4, ZnFe2O4, CoFe2O4 by high-temperature hydrolysis with hydrochloric acid regeneration.

Relevance: The project aims to develop a technology for processing pyrite concentrates using high-temperature hydrolysis with hydrochloric acid recovery and the production of ferrite and metal oxide powders with compositions of NiFe₂O₄, ZnFe₂O₄, and CoFe₂O₄. In Kazakhstan, the nanometallurgy sector is underdeveloped, and there is a lack of effective, waste-free technologies for producing ferrites and metal oxides. Therefore, key objectives include utilizing industrial by-products, optimizing the selection of raw materials, and establishing a hydrochloric acid regeneration cycle. During the research, the principles of thermal decomposition of chlorides will be studied, and high-purity nanoscale ferrites and metal oxides will be obtained. As a result, the materials obtained will be presented as a high-quality product, free of impurities, suitable for industrial application.

Scientific supervisor: Ph.D., Candidate of technical sciences, Associate Professor, Chepushtanova Tatyana

Expected and achieved results: A comprehensive technology for processing pyrite concentrates has been developed, enabling the production of iron oxide pigments (Fe₂O₃ and Fe₃O₄), as well as ultradisperse metal powders and ferrites. The process involves low-temperature chlorinating calcination of pyrite slags followed by percolation leaching. Simultaneous distillation and capture of chloride sublimates are carried out in bubblers and electrostatic precipitators. NaCl, MgCl, CaCl, and gaseous chlorine were used for chlorination; it was established that the optimal temperature range is between 1000 and 1150 °C. These conditions ensure the sublimation of up to 25% nickel and up to 7% cobalt. A technology for producing ferrite precursors NiFe₂O₄, ZnFe₂O₄, and CoFe₂O₄ from chloride solutions via high-temperature hydrolysis for the processing of pyrite-cobalt concentrates was developed for the first time. It was established that the particle sizes of the ferrite powders obtained by SEM-EDS range from 5 to 20 nm. The density of the reduced iron powder (FeCl₂) after calcination was approximately 96%, which exceeds that of iron carbonyl (~92%). This demonstrates the effectiveness of the high-temperature hydrolysis and crystallization technology. The acid-based technology involves the processing of pyrrhotite-cobalt concentrates to produce ultradisperse powders, non-ferrous metals, and ferrites while simultaneously regenerating hydrochloric acid.

List of publications with links to them

1. Chepushtanova T., Altmyshbayeva A., Merkibayev Y., Yespenova Z., Mishra B. Development of technology for processing pyrite–cobalt concentrates to obtain pigments of the composition Fe₂O₃ and Fe₃O₄ // Metals. – 2025. – Vol. 15, No. 8. – Art. 886. – DOI: https://doi.org/10.3390/met15080886.
2. Seredavina T., Zhapakov R., Murzalinov D., Spivak Y., Ussipov N., Chepushtanova T., Bolysbay A., Mamyrbayeva K., Merkibayev Y., Moshnikov V., Altmyshbayeva A., Tulegenov A. The analysis of the ZnO/Por-Si hierarchical surface by studying fractal properties with high accuracy and the behavior of the EPR spectra components in the ordering of structure // Processes. – 2025. – Vol. 12, No. 11. – Art. 2541. – DOI: https://doi.org/10.3390/pr12112541.
3. Чепуштанова Т.А., Алтмышбаева Ә.Ж., Меркибаев Е.С., Мамырбаева К.К. Способ переработки пиритно-кобальтового концентрата : уведомление о положительном результате формальной экспертизы по заявке на изобретение № 2025/0514.1 от 30.05.2025. – Казахстан : РГП на ПХВ «Национальный институт интеллектуальной собственности» МЮ РК, 2025. – № 2025-47808.