Krasnogorov V. O., Deputy Head of Laboratory, ph. +7 (4842) 54-30-08; Putilov Yu. G., Deputy Science Director, ph. +7 (4842) 54-45-82; Tupikov D. Yu., Deputy Director on Magnetic Separation, ph. +7 (4842) 79-42-68; Research & Production Company «Erga» (Russia).

The article describes the scientific research results and developments of the Scientific Production Association (SPA) «Erga» in the field of large-lump ore material magnetic sorting by way of example of coarsely-crushed magnetite ore concentration technology with removal of on-specification product and separation of low-grade rock. The Olenegorsky Mining Complex Komsomolsky Pit ore sample concentration testing stages are considered in detail:

— 2.3-ton, –350+0 mm size representative sample magnetic sorting on a one-of-a-type bench-test installation of SPA «Erga» for the purpose of large-lump product separation into magnetic and non-magnetic components;

— –20+0 mm size fraction separation from magnetic fraction, earlier produced by ore-sorting, with subsequent separation on high-rate drum-type magnetic separator, providing a possibility for low-grade ore fines removal;
— crushing of –350+20 mm size material of ore-sorting magnetic component to –200, –100 and –50 mm size with subsequent separation of each size fraction with a view to determine material liberation degree, required for effective dry magnetic separation.
The conducted tests results verify the possibility of large-lump material effective sorting with separation of non-magnetic product (yield — 45 % from starting sample), consisting of low-grade rock with minimal content of magnetite iron (0.76 %). Subsequent classification of ore-sorting magnetic fraction and dry magnetic separation of –20+0 mm size fraction on drum-centrifugal separator provide for additional removal of 15 % final tailings.