Increasing of efficiency of dry magnetic enrichment of magnetite ore

Abstract

A possibility of sintering ore obtaining from regular skarn magnetite ore by dry magnetic separation considered (DMS). A possibility of decreasing iron losses with DMS tails by additional control operation and application of separators of various design as well as application of screening studied. It was shown, that re-cleaning of intermediate product of –15+0 mm size enables to obtain from a regular skarn magnetite ore, a sintering ore having iron mass share more than 45% at the yield of 5.5% (of DMS intermediate product). It can be reached by application of a suspended belt separator with flat magnetic system. By using a drum separator with increased drum rotation speed, a DMS concentrate was obtained having iron mass share of 43.08%. Application of additional control operation of DMS tails enables to decrease the iron mass share in DMS tails from 11.25–11.32 to 9.97–10.67% as well as iron losses with DMS tails by 11.13–26.06% (rel.). To decrease the iron losses with DMS tails it is reasonable to increase magnetic field induction of drum separators of basic operation, but not apply additional control DMS operation. It was established, that the basic iron losses relate to fine class (–3+0 mm), characterized by increased iron mass share (14.43%). Therefore, for reextraction of iron from DMS tails a scheme with screening at 3 mm sieve and DMS of the mesh minus is possible. Such a scheme enables to obtain an intermediate product having iron mass share of 35.05–45.74% from DMS tails.