Beneficiation process for treating high-iron-carbonate poor-magnetic red mixed iron ore

Abstract

The invention relates to a beneficiation process for treating a high-iron-carbonate poor-magnetic red mixed iron ore, which means a ''stage grinding-magnetic separation-magnetizing roasting- flotation'' beneficiation process. The process comprises the step of feeding a raw ore into first-stage closed-circuit ore grinding to obtain a first-stage closed-circuit ore grinding overflow product, whereinfirst-stage weak-magnetic strong-magnetic coarse grain tailing discarding operation, second-stage closed-circuit ore grinding operation, second-stage weak-magnetic strong-magnetic separation operation, a strong-magnetic ore sorting process and a weak-magnetic ore sorting process are included; the second-stage weak-magnetic strong-magnetic separation operation is used to treat the second-stage closed-circuit ore grinding operation overflow product; a second-stage weak magnetic machine concentrate product is treated in the strong magnetic ore sorting process; and a second-stage strong magneticmachine concentrate product is treated in the weak magnetic ore sorting process. The process has advantages that 1) iron carbonate ore particles are magnetized and roasted, cost is reduced, and ironcarbonate is effectively recycled; 2) magnetite concentrate is magnetically screened in advance; 3) tailing discarding is performed in a strong magnetism state in stages, discarding is performed as much as possible, energy is saved and consumption is reduced; and 4) a concentrate grade and a recovery rate are increased, and a utilization rate of iron ore resources is improved.

Description

technical field [0001] The invention belongs to the field of mineral processing technology, and in particular relates to a mineral processing process for processing high-carbonic acid iron-lean magnetic red mixed iron ore, that is, a "stage grinding-magnetic separation-magnetization roasting-flotation" mineral processing process. Background technique [0002] Under the current mineral processing technology conditions, iron ore containing iron carbonate is a typical refractory iron ore. For a certain iron ore, the raw ore grade is as low as 22% to 24%. The iron minerals in the ore are mainly magnetite, accounting for 40% to 50% of the iron mineral content in the ore; iron carbonate accounts for 27% to 31% of the iron mineral content in the ore. %; hematite and limonite account for 19% to 22% of the iron mineral content in the ore; the rest is iron silicate with less content, and the gangue minerals are mainly SiO 2 ; The particle size of iron mineral intercalation is uneven,...

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Problems solved by technology

Since the ore contains not only a large part of magnetic iron, but also a part of iron carbonate and red limonite that can be selectively utilized, but the single weak magnetic separation-fine sieve process produces iron carbonate and red limonite These two parts of iron ore cannot be effectively recovered, and all of them are thrown out as final tailings, resulting in a low final concentrate yield, only about 20%, and a high final comprehensive tailings, as high as 16% to 19%. The recovery rate is low, only about 48%;

[0006] 2) The process did not select the coarse-grained magnetite part in time, resulting in over-grinding of this part of the iron ore, which not only increased the energy consumption of the grinding, but also caused magnetic inclusions in the subsequent magnetic separation, and the separation effect was poor. Low recycling efficiency;

[0007] 3) It is unreasonable to use a fine screen with an aperture of 0.075mm for quality improvement and screening, because the iron minerals embedded with fine particles have not been dissociated from the monomers under the condition that the final grinding particle size is -200 mesh 90% to 93% , although the under-screen product has gone through two stages of dehydration and one stage of magnetic separation, it is difficult to improve the final concentrate grade, which can only reach 62% to 64%; the dissociation degree of fine-grained iron mineral monomers reaches 90% % above, the grinding particle size must reach -325 mesh above 95%

[0008] 4) The size of the 0.075mm sieve hole is relatively small, resulting in a large amount of return on the sieve, increasing the energy consumption of the grinding, affecting the grinding effect, and reducing the processing capacity of the mill; and because the sieve hole is too thin, it is easy to be blocked, resulting in washing and flushing of the sieve. , Changing the sieve frequently affects the operation rate of the equipment

[0009] Obviously, it is unreasonable to adopt the process of "stage grinding-single magnetic separation-fine sieve regrinding" for magnetite-depleted mixed iron ore containing iron carbonate whose useful minerals are mainly magnetite, and as the ore The iron carbonate content in medium is gradually increasing, and it is unrealistic to continue to ignore the recovery of iron carbonate, hematite and limonite, and the original technological process needs to be improved urgently

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