A lean magnetite beneficiation method capable of reducing the grinding fineness

Abstract

The invention relates to a lean magnetite beneficiation method capable of reducing fineness of grinding ore, which comprises the following process steps: (1) finely grinding crushed lean magnetite ore and then carrying out primary coarse particle magnetic separation; (2) classifying primary coarse particle magnetic separation magnetic concentration by adopting a high frequency fine screen; (3) carrying out secondary ore grinding on oversize products and then carrying out secondary coarse particle magnetic separation; (4) returning secondary coarse particle magnetic separation magnetic concentration to the high frequency fine screen in step (2) to be reclassified, and repeating the operations of steps (2) to (6); (5) carrying out fine magnetic separation on high frequency undersize products; (6) carrying out fine separation on fine magnetic separation magnetic concentration by adopting a magnetic separation column so as to obtain iron ore concentration, returning magnetic separation column tailings to the secondary ore grinding procedure in step (3) and repeating the operations of steps (3) and (4). The granularity of -0.074 micrometers of iron ore concentration separated by the method disclosed by the invention accounts for 35-88%, which is reduced by more than 10% compared with iron ore concentration obtained by a conventional dressing production procedure, iron grade is 65-69%, and iron recovery rate is 45-97%.

Description

technical field [0001] The invention belongs to the technical field of mineral processing, and in particular relates to a lean magnetite beneficiation method capable of reducing the grinding fineness. Background technique [0002] Iron ore is the earliest discovered, the most widely used and the largest resource among many mineral resources, and it is also one of the most important strategic resources in my country. The main characteristics of my country's iron ore are: (1) The reserves are large, but almost all of them are lean ore, with an average iron grade of 32%, which requires ore processing; (2) There are many types of iron minerals, such as magnetite, hematite, Limonite, siderite, ferric silicate, etc., 97.5% of iron ore in my country need beneficiation treatment; (3) The crystal grain size is coarse and fine, and it is difficult to control the grinding fineness with conventional beneficiation process. In particular, the rapid increase in demand for iron ore in the p...

AI Technical Summary

Problems solved by technology

There is a large difference in the size of mineral crystal particles in ore. If the grinding fineness is continuously increased to dissociate more mineral particles, it will inevitably cause "over-grinding" phenomenon of some mineral crystal particles, and "over-grinding" will cause Causes secondary pollution of mineral crystals; but does not increase the grinding fineness, and some mineral crystal particles have not yet been "dissociated", and cannot be effectively sorted, which may cause a decline in the grade of the concentrate, or make this part of the minerals dissociate Tailings discharge, resulting in lower recovery rate and waste of resources

[0004] Improving the grinding fineness will prolong the grinding time. First, it will increase the energy consumption, thereby increasing the cost of ore dressing; second, it will reduce the processing capacity of the ball mill, resulting in a decline in concentrate output; third, due to the crystallization of some minerals The particles appear "over-grinding", causing the mineral crystals to be polluted, making it difficult to improve the concentrate grade

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