High-pressure rolling and magnetic-gravity separation process for lean hematite

Abstract

The invention relates to a high-pressure rolling and magnetic-gravity separation process for lean hematite. The high-pressure rolling and magnetic-gravity separation process for lean hematite is characterized by comprising the following steps that after raw ore particles with the particle size of 0-300 mm are subjected to the coarse crushing and intermediate crushing screening operation, the product particle size is 0-35 mm; after the particles pass through a high-pressure roll mill and a wind grading system, the large-particle-size products subjected to wind grading return to the high-pressure roll mill, the small-particle-size products subjected to wind grinding and with the 200-mesh sieve sieving rate being 90%-95% are fed to the technical procedures with low intensity magnetism, high intensity magnetism and a centrifugal machine so as to be graded; concentrate obtained through low intensity magnetic separation and concentrate obtained through the centrifugal machine are combined into final concentrate with the grade being 66.5%-67.5% and the yield being 27%-29%; and the grade of tailings of high intensity magnetic separation is 8.3%-8.8%, the grade of tailings of two-stage scavenging centrifuge is 16%-18%, and the tailings of high intensity magnetic separation and the tailings of two-stage scavenging centrifuge are combined into final tailings with the grade being 10.50%-11% and the yield being 61%-63%. The high-pressure rolling and magnetic-gravity separation process for lean hematite has the advantages that original fine crushing operation and two-stage grinding operation are omitted, the products with the 200-mesh sieve sieving rate being 90%-95% can be directly obtained by the adoption of the high-pressure roll mill and the wind grading system, the process structure is simplified, and the ore separation cost is reduced significantly.

Description

Technical field [0001] The invention belongs to the technical field of mineral processing, and particularly relates to a high-pressure roller mill and magnetic-gravity separation process of lean hematite. Background technique [0002] Lean hematite is usually sorted by "three-stage crushing, two-stage continuous grinding, weak magnetic-strong magnetic-anion reverse flotation" process. That is to say, lean hematite ore 300~0mm, after coarse crushing, medium crushing and fine crushing, a product with a particle size of -12mm or more than 90% is formed. After two stages of continuous grinding, (one stage grinding and The primary classification forms a closed-circuit grinding, the second-stage grinding and the second-stage classification form a closed-circuit grinding), the overflow particle size of the secondary classification reaches -200 mesh and the content is 88-90%, and the secondary classification overflow product is fed to the first-stage weak magnetic separator For sorting,...

AI Technical Summary

Problems solved by technology

[0003] After coarse crushing, medium crushing, and fine crushing and screening, the particle size of the raw ore reaches -12mm90% or more, and the process of "two-stage continuous grinding, weak magnetic-strong magnetic-anion reverse flotation" is adopted for separation, and three stages are used in the process Crushing and two-stage grinding operations have the disadvantages of large number of separation stages, long process, high mineral processing cost and complicated process

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