Hematite stage grinding, magnetic separation-gravity separation-acid positive flotation process

Abstract

The invention relates to a hematite stage grinding-magnetic separation-reselection-acid positive flotation process which comprises the steps of raw ore, first-stage grinding and first-stage classification. The process is characterized in that the first-stage classification overflow is fed to medium magnetism; the concentrate of the medium magnetism is subjected to rough and fine classification; the tailings of the medium magnetism is fed to strong magnetism after carrying out concentration and deslagging operation before strong magnetism; the strong magnetic ore is subjected to rough and fineclassification; a rough particle product obtained by rough and fine classification is reselected; the reselected tailings is subjected to two-stage classification; the middle ore of a trochus is returned to the trochus; the two-stage classification overflow is returned to the medium magnetism; the two-stage classification sank sand is subjected to two-stage grinding; the discharge ore of the two-stage grinding is returned to the two-stage classification; the separated fine particle product is subjected to acid positive flotation operation after concentrated; the flotation concentrate and the reselected concentrate are mixed into final concentrate; and the flotation failings and the strong magnetic tailings are mixed into final tailings for discarding. The invention has the advantages of simple process flow, convenience in control, stable technical index, good effects of energy saving and emission reduction and more ideal effect on processing low-grade ore.

Description

technical field [0001] The invention relates to the technical field of mine beneficiation engineering, in particular to a hematite stage grinding, magnetic separation-gravity separation-acid positive flotation process. Background technique [0002] Hematite ore is an important type of iron ore in my country. The typical hematite ore beneficiation process in the 1990s is stage grinding, coarse and fine separation, gravity separation-magnetic separation-acid positive flotation. A grading overflow is divided into coarse and fine products through coarse and fine grading. The coarse-grained part undergoes coarse snail, fine snail, and snail sweeping operations to select the gravity-concentrated ore, and the tailings are thrown away by the weak magnetic field and the medium magnetic field, and the medium ore is fed into the second-stage grinding. The second-stage grinding is open-circuit grinding, and the second-stage classification overflow is mixed with the second-stage ba...

AI Technical Summary

Problems solved by technology

The disadvantages of this technological process are: 1. A section of graded overflow (the content of -200 mesh particle size accounts for 50-70%, and the dissociation degree of iron minerals and gangue minerals is higher than 50%) can be completely separated by magnetic separation. The tailing is directly thrown without going through coarse and fine classification, coarse snail and snail sweeping operations, so the process is complicated, energy is wasted, and the separation efficiency is low; 2. The secondary grinding operation adopts open-circuit grinding, and the particle size is unstable, which is easy to cause Process indicators fluctuate; 3. The fine-grained operation process is unreasonable. The grades of magnetic separation concentrate and flotation concentrate are both 60-62%, resulting in a comprehensive concentrate grade of only 63-63.5%.

Although this technological process improves the comprehensive concentrate grade to 65-67.5%, there are still some deficiencies: 1. One-stage graded overflow (-200 mesh particle size accounts for 50-70%, iron minerals and gangue minerals The degree of dissociation is higher than 50%), and the tailing can be directly carried out by the magnetic separation method, without having to go through coarse and fine classification, coarse snails and snail sweeping operations, so the process is complicated, energy is wasted, and the separation efficiency is low; 2. Secondary The grinding operation also adopts open-circuit grinding, and the particle size is unstable, which is likely to cause fluctuations in process indicators; 3. There are many types of flotation reagents, generally four: modifier alkali, inhibitor corn starch, activator lime and collector fatty acid anion-like organics

The transportation, storage, preparation, and addition of medicaments are troublesome, and lime is prone to failure, and cornstarch is a food source that is scarce; 4. The pH value of the concentrate is generally above 10, and the slurry is very sticky, and it is difficult to filter and dehydrate. It is necessary to reduce the pH value to 7-8 by adding acid to remove the adsorption of corn starch on the surface of the concentrate to improve the filtration and dehydration effect.

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