Classification grinding separation process for preselected coarse-grained concentrate of lean hematite

Abstract

The invention relates to a classification grinding separation process for preselected coarse-grained concentrate of lean hematite. The process comprises the step of feeding the lean hematite with the grade of 24%-26% into a coarse grain wet type preselection process to obtain the preselected coarse grain concentrate. The process is characterized in that a pre-grading, stage grinding and stage strong magnetic tailing discarding-reverse flotation process is adopted in subsequent treatment, specifically, the process specifically comprises the following steps that 1, the pre-selected coarse grain concentrate is fed into a flat-bottom concentration grading cyclone to be graded in advance, and pre-graded settled sand and pre-graded overflow are obtained; 2, the pre-graded settled sand is fed into a first-section ball mill, and the pre-graded overflow is directly fed into a secondary cyclone; and 3, second-stage bulk concentrate is subjected to reverse flotation, and final flotation concentrate with the grade being 65%-66% and the yield being 25%-27% is obtained through one-time roughing, one-time concentration and three-time scavenging. The process has the advantages that: 1, the concentration requirement of the first-stage mill is met, and the production is stable; and 2, fine grain products are graded in advance, the load of a first-stage mill is reduced, the energy is saved, and the consumption is reduced.

Description

technical field [0001] The invention belongs to the technical field of beneficiation technology of lean iron ore, and in particular relates to a grading and grinding process of pre-selecting coarse-grain concentrate of lean hematite. Background technique [0002] A concentrator adopts the process of "coarse-grained wet pre-selection, stage grinding, stage strong magnetic tailing-reverse flotation" to process a kind of extremely poor hematite ore. Among them, in this process, firstly, the poor hematite ore with a grade of 24%~26% after coarse crushing is fed into the semi-autogenous mill, and the ore discharged from the semi-autogenous mill is fed into a linear vibrating screen with a sieve size of 3 mm. , the products on the sieve are returned to the semi-autogenous mill, the products under the linear vibrating screen with a particle size of 3-0 mm are fed into the wet pre-selection weak magnetic separator, and the tailings of the pre-selected weak magnetic separator are fed...

AI Technical Summary

Problems solved by technology

There is a problem in the specific production: due to the relatively coarse particle size of the pre-selected coarse-grained concentrate, a section of the conventional hydrocyclone grit outlet wears too fast, and the particle size of the overflow product cannot be guaranteed, which affects the normal operation of subsequent sorting operations.

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