Process for roasting, stage grinding, coarse-fine grading and reselection-magnetic separation of hematite

Abstract

The invention relates to a process for the roasting, stage grinding, coarse-fine grading and reselection-magnetic separation of hematite. The process is characterized by comprising the following steps of: demagnetizing effusion subjected to first-section grading, and performing coarse-fine grading; performing coarse screwing on coarse grains, and performing first-section permanent magnetism on fine grains; performing fine screwing on concentrates subjected to the coarse screwing, and performing the permanent magnetism on tailings subjected to the coarse screwing; returning middlings subjectedto the fine screwing to a fine screwing process, and performing second-section demagnetizing on tailings subjected to the fine screwing; performing the second-section demagnetizing on concentrates subjected to the permanent magnetism, and performing middle magnetic separation on tailings subjected to the permanent magnetism; performing the second-section demagnetizing on concentrates subjected tothe middle magnetic separation to enter a second-section grading process, returning effusion subjected to second-section grading to the coarse-fine grading process, and performing second-section grinding on silt subjected to the second-section grading; returning products subjected to the second-section grinding to a second-section demagnetizing process; dewatering concentrates subjected to first-section demagnetizing, and performing second-section permanent magnetism on the dewatered concentrates; and mixing the concentrates subjected to the second-section permanent magnetism and concentratessubjected to the fine screwing to form final concentrates, and mixing tailings subjected to the first-section permanent magnetism, dewatered tailings, tailings subjected to the second-section permanent magnetism and tailings subjected to the middle magnetic separation to form final tailings and discarding. The process has a simple flow, and is convenient to control and stable in technical indexes.

Description

technical field [0001] The invention relates to the technical field of mine beneficiation engineering, in particular to a hematite roasting, stage grinding, coarse and fine grading, gravity separation-magnetic separation process. Background technique [0002] Hematite ore is an important type of iron ore in my country. The traditional hematite roasting-magnetic separation beneficiation process is to roast the raw ore with a grade of 25-30% and feed it into a closed-circuit grinding operation consisting of one-stage grinding and one-stage 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 fine snail operation. Closed-circuit grindi...

AI Technical Summary

Problems solved by technology

[0004] 1. The medium magnetic operation is in the front, and the coarse and fine classification operations are in the back. Although the demagnetization treatment is carried out, the gravity separation is still affected by the magnetic agglomeration, and the concentration grade of the gravity separation is only 63-64%.

The separation efficiency of permanent magnet and fine sieve is not high, and the sieve fine grade is only 62-63%, resulting in a comprehensive concentrate grade of only about 63%, combined with a comprehensive tailings grade of about 10-11%, the technical indicators are not ideal;

[0005] 2. The products on the sieve are fed into the coarse screw operation of gravity selection, the separation effect of fine particle operation affects the coarse particle operation, the process is difficult to control, and the index is easy to fluctuate

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