Hematite roasting, stage grinding, intermediate magnetic separation, fineness classifying, gravity concentration-magnetic separation technique

Abstract

The invention belongs to the technical field of iron ore grading and especially relates to a hematite roasting, stage grinding, intermediate magnetic separation, fineness classifying, gravity concentration-magnetic separation technique, comprising raw ore roasting, first segment of closed loop grinding, primary grading, intermediate magnetic separation, fineness classifying and gravity concentration-magnetic separation. The technique is characterized by feeding the intermediate magnetic separation concentrate in a demagnetizer, grading the concentrate through fineness classifying, grading the material into rough granule level product and fine granule level product, feeding the rough granule level product in the fineness classifying procedure in a helical chute, demagnetizing the concentrate in the helical chute and performing screening procedure on the concentrate, serving the tailings in the helical chute and the oversize product in the screening procedure as middlings, performing secondary grading and second segment of closed loop grinding procedures on the middlings, and feeding the fine granule parts in the fineness classifying procedure in a dehydration tank, a permanent magnetic machine and a magnetic field screening machine to perform magnetic separation procedure. The comprehensive concentrate is composed of screening concentrate and magnetic field screening machine concentrate, and the compressive tailings are composed of intermediate magnetic separation tailings, dehydration tank tailings, permanent magnetic machine tailings and magnetic field screening machine tailings. The technique has the advantages that the sorting efficiency of the whole procedure is improved, the screening concentrate in rough granule procedure and the magnetic field screening machine concentrate in fine granule procedure can reach 65-67%, the level of the comprehensive concentrate is higher than 65-67%, and the level of the compressive tailings is reduced to 8-10%.

Description

technical field [0001] The invention belongs to the technical field of iron ore separation, and in particular relates to a process of hematite roasting, stage grinding, neutral magnetism, coarse and fine grading, and gravity-magnetism. Background technique [0002] Hematite ore is an important type of iron ore in my country. Roasting of hematite - magnetic separation is a traditional beneficiation process. as attached figure 1 As shown, the raw ore with a grade of 25-30% is roasted and fed into a closed-circuit grinding operation consisting of one stage of grinding and one stage of classification. A graded overflow is fed into the medium magnetic operation, and the medium magnetic concentrate is fed into the coarse and fine classification operation after demagnetization and classified into coarse and fine products. The coarse part is fed into the gravity separation operation, and the grade of 63-64% gravity separation concentrate is selected through the coarse snail and f...

AI Technical Summary

Problems solved by technology

[0003] This process mainly has the following disadvantages: 1. Since the spiral chute is sorted according to the specific gravity and particle size difference of the minerals, the gravity concentrate ore concentrate is the product of the inner edge of the fine snail layering and zoning—fine It is obtained from the high-grade concentrate of particles and the rich conjoint body of coarse particles. In addition, due to the influence of magnetic agglomeration, the grade of gravity-selected concentrate is only 63-64%.

2. The permanent magnet and fine sieving operations of the fine-grained part are affected by magnetic inclusions, magnetic agglomeration, etc., so the separation efficiency is not high, and the sieve fine grade is only 62-63%; The grade is also about 10-11%, and the technical indicators are not ideal; 4. The product on the sieve is fed into the coarse snail operation of gravity selection, and the separation effect of fine-grained operation affects the coarse-grained operation. easy to fluctuate

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