Pre-selection method for low-grade hematite-containing waste rock

Abstract

The invention discloses a pre-selection method for low-grade hematite-containing waste rock. The pre-selection method comprises: fragmenting low-grade hematite-containing waste rock raw ore with the iron grade of 18-23% to 40-0 mm through coarse crushing and intermediate crushing work, employing a permanent-magnet dry type high-intensity magnetic separator to perform pre-selection, controlling the cylinder surface magnetic field intensity of the permanent-magnet dry type high-intensity magnetic separator to be 0.8-1.0 T, controlling the cylinder surface linear velocity, the separation baffle plate distance and the material layer thickness, and throwing out coarse-grain tailings with the iron grade less than 14.0%; grinding the rough concentrate obtained through permanent-magnet dry type high-intensity magnetic separation to 10-0 mm through a high-pressure roller, then preselecting by an electromagnetic pulsation high-gradient coarse-grain wet-type high-intensity magnetic separator, and then throwing out fine-grain tailings with the iron grade of 11% or less, so as to obtain rough concentrate which is sent to a main workshop for grading through a grinding selection technology. According to the method, a large amount of tailings are thrown out through magnetic pre-selection before ore grinding, the ball milling amount of the ore is reduced, the ball milling grade is improved, the ore grinding energy consumption is reduced, the method has the advantages of simple structure, short flow, low energy consumption, strong adaptability and high ore selection technology index, is widely applicable to hematite selection factories, and is especially suitable for pre-selection of low-grade hematite-containing waste rock.

Description

technical field [0001] The invention relates to a pre-selection method of iron ore, in particular to a pre-selection method of waste rock containing hematite, which can also be used for hematite ore, and can be widely used in hematite dressing plants, and is suitable for processing iron ore Pre-selection of low-grade hematite-containing waste rock with a grade of 18%-23%, especially suitable for pre-selection of low-grade hematite-containing waste rock with a raw ore iron grade of 18.0-22.0% and iron minerals mainly hematite . Background technique [0002] According to the data survey, countries rich in iron ore resources abroad, such as Brazil, Australia, South Africa, India, etc., are the main importers of iron ore in my country. They mainly mine and select rich ore that is easy to mine. ≤40% iron ore, and low-grade hematite resources with iron grade ≤23% have not been developed and utilized. [0003] At present, due to the constraints of the state of ore occurrence, the ...

AI Technical Summary

Problems solved by technology

According to the current technical equipment level of the relevant ore concentrators, when the price of iron ore concentrate is at a high level, waste rock containing hematite can only be used in a small amount by appropriately lowering the cut-off grade of mining, but most of the ore can only be treated as surrounding rock, not only Cause waste of resources, occupy land, and pollute the environment

The bottleneck problem in resource utilization of hematite-containing waste rock is: on the one hand, due to the lack of efficient pre-selection technology and equipment for low-grade hematite-containing waste rock, such as direct selection of waste rock, the beneficiation ratio of the concentrator is as high as 5-6, resulting in A large amount of waste of energy, materials, and mineral processing agents is caused, and the production cost is high, which is unbearable for enterprises; on the other hand, a large amount of fine-grained tailings are generated during the mineral processing process, which further aggravates the pressure on environmental protection and safety.

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