| Popis: |
On the example of a sample of ferruginous quartzites from the Olenegorskoye deposit, the possibility of preliminary concentration by dry magnetic separation (DMS) has been established. The mineralogical and petrographic studies have shown that, in terms of their textural and structural features and mineral composition, ferruginous quartzites may be divided into two types, differing in the amount of hematite included in their composition, which indicates the possibility of using DMS to generate the following three separation products: magnetite, hematite-magnetite, and rock. DMS with the use of a laboratory drum magnetic separator allowed selecting the upper size limit of 80 mm for lumps entering the separation. At the same time, 24.7 to 26.0 % of all waste and low-mineralized rocks with the mass fraction of Fetot of 4.51 to 6.07 % are transferred to the non-magnetic fraction during the separation of classes of –80+50 and –50+25 mm. For the size class of –25+10 mm, the yield and Fetot values are within the same limits. It has been shown that sulfidecontaining rocks and rocks of increased strength (with the strength coefficient of at least 23) are separated into the non-magnetic fraction. The strength of ferruginous quartzites does not exceed 20. This rock strength ratio confirms improved crushing and grinding efficiency. The possibility of separation of the magnetic fraction with the particle size of –80+25 mm into the following products has been established: the magnetite-hematite product (MF-1 + MF-2) with the mass fractions of Femagn 43.3% and Fehem 14.9 %, and the predominantly hematite product (MF-3 + MF-4) with the mass fractions of Femagn 1.1 % and Fehem 67.9 %. |
