JSC “Mekhanobr Engineering” (St. Petersburg, Russia)

Gapeeva A. E., Researcher, gapeeva.ae@mekhanobr.com
Taranov V. A., Candidate of Technical Sciences, Head of Technological Research Department, taranov@mekhanobr.com
Tasina T. I., Senior Researcher, Deputy Head of Technological Research Department, science@mekhanobr.com
Aksenova G. Ya., Candidate of Geological and Mineralogical Sciences, Leading Researcher, aksenova.gy@mekhanobr.com

The article presents the results of research on the development of a beneficiation technology for iron ore with a high sulfur content. The work was carried out on a representative sample of iron ore containing 39.6% total iron and 2.63% total sulfur. The relevance of the study was driven by the need to obtain a high-quality concentrate with a low sulfur content. The concentrate obtained after the third stage of wet magnetic separation contained 68% total iron and 3.2% total sulfur. The high sulfur content is attributed to the presence of iron sulfide minerals, namely pyrite and a significant amount of monoclinic pyrrhotite. Monoclinic pyrrhotite exhibits high magnetic susceptibility, which results in the formation of magnetic floccules consisting of finer magnetite particles around the pyrrhotite grains. To reduce the sulfur content in the magnetic product of the third-stage wet magnetic separation, flotation tests were carried out. The results of experiments on the selection of a reagent regime for pyrrhotite flotation are presented, and a comparison is made between the results obtained without and with the use of a scrubbing operation. It was found that the combination of the scrubbing operation together with sodium silicate makes it possible to reduce the sulfur content in the underflow product to 0.28% with a sulfur recovery of 91.73% to the froth product. The iron content in the concentrate meets the high standards of metallurgical production (69.0%), ensuring high quality of the feed material for smelting with minimal impurities, since an elevated sulfur content leads to a deterioration in the mechanical properties of pellets. Such a high-quality magnetite concentrate is primarily used in ferrous metallurgy for the production of high-grade steels and cast irons.

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