Refractory iron ore on-line closed-loop shaft furnace roasting, dry grinding and dry separation technology

Abstract

The invention discloses a refractory iron ore on-line closed-loop shaft furnace roasting, dry grinding and dry separation technology which comprises the following steps that oxidized refractory iron ore with the size fraction being +15 mm to -100 mm is subjected to magnetizing roasting through a shaft furnace, and the roasted ore is cooled to the normal temperature; the roasted ore is subjected to dry-type pre-separation and discarded through magnetic pulleys; after discarding is finished, the roasted ore is subjected to dry grinding and dry separation, specifically, dry grinding is conducted till the ore with the size fraction being -0.074mm accounts for 70-80%; a panel wind magnetism combination dry separator is adopted for three-stage dry-type concentration; after two-stage and three-stage tailings are enriched by a spiral dry-type magnetic separator, the enriched tailings, one-stage concentration tailings and discarded waste ore are discharged by qualified tailings, and the grade is controlled to be 10% or below; the enriched concentrate is returned to a newly-built granulating rotary kiln roasting system for closed-loop magnetizing roasting; and concentrate after three-stage concentration is final qualified concentrate, and the grade reaches 60% or above. According to the refractory iron ore on-line closed-loop shaft furnace roasting dry grinding and dry separation technology, aiming at solving the problem of the high grade of shaft furnace magnetizing roasting ore magnetic separation tailings of refractory iron ore with different size fraction ranges, iron resources in the tailings are recovered in an on-line closed-loop mode, and the resource utilization rate is increased.

Description

technical field [0001] The invention belongs to the technical field of mineral processing, and relates to an on-line closed-circuit shaft furnace roasting dry grinding dry separation process for refractory iron ore. Background technique [0002] my country's iron ore resources are rich in lean ore and less in magnetic ore. Weak magnetic iron ore accounts for more than 70% of the total reserves. Weak magnetic iron ore can be magnetically separated after it has been magnetized and roasted to become a strong magnetic mineral. Obtain iron ore concentrates whose quality meets the requirements for sintering ingredients. +15mm~-100mm grain size iron ore is directly magnetized and roasted in a shaft furnace. Since different grain sizes of refractory iron ore have different magnetization roasting characteristics, the roasting time and roasting temperature are different. Magnetized roasting in the furnace inevitably has the problem of uneven roasting quality, that is, there is raw ore...

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Problems solved by technology

[0003] The present invention aims at magnetizing and roasting refractory iron ore in a certain particle size range in a shaft furnace, the quality of the roasted ore is uneven, the grade of the magnetic separation tailings is high, it can be recycled but sent to the tailings dam, the secondary recycling process is complicated and the cost is high Problem, providing an on-line closed-circuit shaft furnace roasting dry grinding dry separation process for refractory iron ore

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