Fine grinding magnetic separation-roasting-regrinding magnetic separation tailings recovery process

Abstract

The invention relates to a fine grinding magnetic separation-roasting-regrinding magnetic separation tailing recovery process. The process is characterized by adopting three-section magnetic separation, three-section cyclone closed-circuit grinding classification operation, roasting and regrinding magnetic separation. A second-section cylindrical magnetic concentrate is singly grinded to reach a particle size of -0.025 mm above 90%; then, the first-section weak magnetic separation is performed to realize sufficient and effective separation of a strong magnetic ore and a weak magnetic ore from a gangue; a first-section weak magnetic concentrate is directly fed to a subsequent weak magnetic separation operation; and when the iron mineral recovery rate is guaranteed, the roasting operation handling capacity is reduced, and the excellent indexes of the concentrate with grade above 65% and yield above 9%, the tailing grade of 5-7% and the metal recovery rate above 53% are obtained.

Description

technical field [0001] The invention belongs to the technical field of iron ore beneficiation, in particular to a tailing recovery process of fine grinding magnetic separation-roasting-regrinding magnetic separation. Background technique [0002] At present, 10% to 15% of the iron ore lost in the comprehensive tailings with a grinding particle size of -0.074mm is 60% to 70% produced by the concentrator using "stage grinding, coarse and fine separation, and heavy-magnetic-flotation combined process" The materials are mainly red limonite and magnetic iron. The current effective process for the recovery of comprehensive tailings is: use two-stage spiral chute for comprehensive tailings, permanent magnet sweeping, and mix spiral concentrate and permanent magnet concentrate to form coarse concentrate. , Coarse concentrate is ground and then selected by weak magnetic, strong magnetic, reverse flotation or centrifuge process. Adopt the "spiral chute, permanent magnet-grinding-stro...

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Problems solved by technology

Therefore, the problem of high grade tailings cannot be solved after the comprehensive tailings are sorted by "spiral chute, permanent magnet-grinding-strong magnetism, centrifuge process", which makes it difficult to further improve the recovery rate

"Magnetic separation-roasting-magnetic separation process" uses strong magnetic to separate the tailings, then roasts all the obtained strong magnetic concentrates, and then uses weak magnetic to separate the roasted ore. Although this process improves the recovery rate , but since the distribution rate of magnetic iron in the tailings is 15% to 40%, this part of the product should not be processed in a roasting process with complicated processes (concentration, filtration, drying, etc. before roasting), high energy consumption, and high cost deal with

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