Development a new flotation refining technology for magnetite concentrates at the Northern Mining and Processing Plant Private Joint-Stock Company

The purpose of this study was to develop a new flotation refining technology for magnetite concentrates at the Northern Mining and Processing Plant Private Joint-Stock Company to produce a final commercial product with a total iron content of at least 69.0% and silica content not exceeding 4%. Mineralogical analysis was used to study mineral liberation, chemical analysis to determine the qualitative composition of the raw material, and sieve analysis to determine the granulometric composition of the material. The study also employed methods of processing, analysing, and synthesising research results to establish optimal conditions for separating mineral grains by size. The results showed that achieving the maximum total iron content in the concentrate and minimising the silica content, while ensuring maximum iron recovery, depends on grinding conditions, which are determined by the degree of mineral grain liberation. It was found that the flotation rate constant for quartz depends on the mass fraction of quartz in the feed and ranges from 0.05 to 0.10 min-1. Mineralogical studies of the raw concentrate revealed that, in addition to monomineral magnetite particles, it includes aggregates of magnetite-quartz (up to 2.52%), magnetite-quartz-silicate, magnetite-quartz, silicate-carbonate (up to 7.5%). Carbonates are mainly represented by sideroplesite and calcite; silicates by cummingtonite, biotite, and chlorite. Gangue particles consist of monomineral quartz or silicate-quartz, carbonate-silicate-quartz aggregates. According to quantitative mineralogical calculations, monomineral magnetite particles are concentrated in the fine-grained fraction, with 92.3% in the -0,045+0.02 mm class and 98.1% in the -0.02 mm class. Laboratory tests of the magnetic-flotation refining of the concentrate demonstrated the feasibility of obtaining high-quality concentrate from the magnetite concentrates of the Northern Mining and Processing Plant Private Joint-Stock Company with a total iron content of 69.0% and silica content of 3%, achieving an 88.9% yield and 92.9% iron recovery in the concentrate from the operation. The practical significance lies in the development of a technological scheme for refining raw magnetite concentrate under the conditions of the Northern Mining and Processing Plant Private Joint-Stock Company to produce high-quality concentrate with maximum yield, a total iron content above 69.0%, and silica below 4.0%, while ensuring iron recovery in the concentrate of more than 90%