Abstract: In order to make sure 6 300 000 ton high mud content lean hematite at Sijiaying area pass the one stage separation system successfully, size-fractionated high intensity magnetic preconcentration was done on representative ore sample in the laboratory. The study indicates, size fraction sample of 13～6、6～2 mm could not discarding waste normally, but put into the pre-process system to handle them directly;the effect of wet high intensity magnetic preconcentration of size fraction sample of 2～0 mm is good,which could discard the qualified tailings of operation yield 50% around,discarding of a great deal of high mud content tailings are helpful to the stability of production system and mineral processing index.

Key words: High-clay and lean hematite, Dry-type high intensity magnetic preconcentration, Wet type high intensity magnetic preconcentration