Technological solutions to increase the level of iron extraction from stored enrichment tailings

This article presents the main results of research on the extraction of iron from the waste of the processing plant stored in the tailings dump. The average sample was classified by granulometric composition and the content of Fe2O3 was determined by the X-ray fluorescence method for each class. It follows from the results of the sieve analysis that the most iron-rich classes are +2 mm and –0.071 mm. The iron content in the +2 mm class approximately corresponds to the iron content in the source ore. When studying samples of grades +0.1–2 mm under a microscope, it was found that magnetite and hematite are bound by clay materials into floccules, which partially disintegrate upon drying. The initial material with a moisture content of 10.7% was pre-prepared for separation: a fraction of +3 mm was dried and removed. The resulting material was separated on a wet magnetic drum separator with sequential cleaning of the non-magnetic fraction in four stages with induction on the working surface of 0.18, 0.3, 0.4, 0.5 Tl. The resulting non-magnetic fraction from wet magnetic separation was separated on a dry roller separator with induction on the working surface of 1.5 Tl. The non-magnetic fraction was divided by screening into fractions: –3+2 mm, –2+1 mm, –1+0.2 mm, –0.2+0 mm. As a result of the experiment, it was found that wet magnetic separation after pre-drying makes it possible to isolate a concentrate with a content of up to 42% by weight of Fe2O3 into an industrial product. The total yield reaches 24.5% at a magnetic field strength of 0.18 Tl. Check-cleaning, as well as dry separation, do not have a significant additional effect. The conducted research and the developed technological scheme have shown the possibility of obtaining iron ore concentrate with an iron content of more than 60% from stored tailings. At the same time, the return of iron to production is 58%.