Coarse and fine separation-gravity concentration-magnetic separation combined beneficiation process for processing Anshan type iron ores

Abstract

The invention relates to a coarse and fine separation-gravity concentration-magnetic separation combined beneficiation process for processing Anshan type iron ores. The process comprises fine crushing, one-stage closed loop ore grinding, coarse and fine grading, gravity concentration and magnetic separation. The process is characterized in that the process is improved such that fine-crushing-ball-milling-grading flows are replaced by roll milling-ball-milling-grading flows; an edge tail product of a coarse screw is added into a fine grain product for selection; pre-grading before a regrind mill is cancelled; and two-stage continuous weak magnetic separation is adopted for the processed fine grain product for taking the concentration, and a reverse flotation operation is replaced by a finegrain gravity concentration operation subsequently. The grade of raw ores is 27-31%, the final concentrate grade is 66.5-67.3%, and the final tailing grade is 7-8.5%. The process has the advantages that 1) the ore grinding efficiency is improved and the machine-hour is increased; 2) the edge of the coarse screw is classified in fine grain product treatment, so that the loss of magnetic fine iron ores in scavenging is reduced; 3) qualified concentrate is yielded by two-stage weak magnetic separation, so that the production cost is lowered; and 4) reverse flotation is replaced by fine grain gravity concentration, so that the agent cost and the ore pulp warming energy consumption are saved.

Description

technical field [0001] The invention belongs to the technical field of mineral processing, and in particular relates to a coarse-fine separation-gravity-magnetic combined mineral separation process for processing Anshan type iron ore. Background technique [0002] Anshan-style iron ore is one of the main iron ore resources in my country. In the current severe situation of the global steel industry, it is particularly important to strengthen the efficient utilization of Anshan-style iron ore. [0003] Anshan-type iron ore is mostly fine-grained disseminated high-silicon-poor iron ore, generally containing about 30% iron and 40%-50% silicon dioxide. The main metal minerals are magnetite, pseudo (or semi-pseudo) hematite, hematite, sometimes with a small amount of limonite, specularite, siderite, etc.; gangue minerals are mainly quartz, followed by hornblende , biotite or pyroxene and other silicate minerals. The outstanding features of this type of ore are as follows: [0...

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Problems solved by technology

[0006] 3) Because the thickness of the ore layer and interlayer in the ore deposit changes from time to time, the properties of the ore often fluctuate, and the size of the embedded iron minerals is uneven, which also brings certain difficulties to the development of this type of ore

[0009] 1) The output of low-cost gravity separation operations is low, and more than 50% of the concentrates are produced by high-cost flotation operations;

[0010] 2) Due to the low intensity of the magnetic field in the sweep, the fine-grained iron minerals that have been dissociated in the feed cannot be effectively recovered, so that their content in the tailings is too high, which increases the risk of Anshan-type iron ore The cost of sorting stones has caused a waste of resources

[0011] 3) The grading efficiency of the pre-grading operation before regrinding is extremely low, only less than 20%, and the effect of pre-grading has not been played;

[0012] 4) The cost of reagents for reverse flotation is high, and heating flotation of ore pulp causes a large amount of energy loss and brings environmental pressure

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