Magnetic-gravity combined ore dressing technology for hematite

The invention discloses a magnetic-gravity combined ore dressing technology for hematite, comprising the following steps of: carrying out dry magnetic separation and jigging gravity separation to obtain blast furnace lump ore, throwing the tailings of the lump ore, carrying out first-stage ore grinding, weak magnetic separation, strong magnetic separation and centrifugal gravity separation on middlings, and carrying out second-stage ore grinding, weak magnetic separation, strong magnetic separation and centrifugal gravity separation. According to the technology, part of qualified blast furnace lump ore (the iron grade is large than 54%) can be obtained in advance, the massive tailings (the iron grade is less than 12%) can be thrown out, the quantity of the ball-milled ore (the middlings) can be greatly reduced, and the grinding and separation energy consumption can be greatly reduced. The massive tailings which are thrown out can replace the macadam and the stone to be taken as the building material, so that