Low-grade bauxite raw ore open-circuit grinding ore beneficiation process

Abstract

The invention provides an open-circuit grinding ore dressing process for low-grade bauxite raw ore. Roughing, sweeping, and beneficiation are used to obtain A / S5.5-6 concentrates, and the underflow or returned sand discharged from the classifier, whose A / S reaches the standard of medium-grade bauxite, and the ore particle size is less than 60 mesh, is fed into the After another mill grinds ore, it is classified by a classifier, and the overflow of <200 mesh accounting for 95% is subjected to roughing, sweeping, and concentration to obtain A / S8-11 concentrate. This process makes full use of the difference in the Mohs hardness of diaspore and kaolinite in low-grade bauxite, and increases the A / S of bauxite concentrate to above 8, which can improve the production of Al 2 o 3 High recovery rate, energy saving, low cost, low alkali consumption, not only can increase production, save energy, reduce cost, high quality, high price, and produce huge economic benefits for beneficiation enterprises, it can also be used in the production of high alumina clay beneficiation enterprises, and can also be used for For the beneficiation of medium-grade bauxite, the concentrate A / S can be stabilized at 11-12.

Description

technical field [0001] The invention belongs to the technical field of mineral processing, in particular to a low-grade bauxite raw ore open-circuit grinding mineral processing technology. Background technique [0002] The crystallization size of beneficial and harmful minerals in bauxite is very fine. The crystallization size of diaspore is 5-10 microns, and the crystallization size of diaspore is only about 5 microns. When beneficiating, it is required that the raw ore should be crushed and finely crushed and then supplied to the beneficiation mill with a particle size of about 20mm. For bauxite grinding, the raw ore must be ground to a fineness of ﹤200 mesh (0.074mm), preferably 95-98%. For this reason, all beneficiation enterprises adopt closed-circuit grinding. [0003] Closed-circuit grinding is realized through the classifier in the grinding system, and some cyclone classifiers or spiral classifiers are used. When a cyclone classifier is used, its overflow requireme...

AI Technical Summary

Problems solved by technology

[0004] At present, the biggest problem with the closed-circuit grinding process is that the main beneficial mineral in bauxite, diaspore (Al 2 o 3 ·H 2 O) Mohs hardness 6-7, the main harmful mineral kaolinite (Al 2 o 3 2SiO2 2 2H 2 O) The difference in Mohs hardness 1-3, especially involves the huge difference in grindability in the mill, that is, kaolinite is easy to grind, diaspore is difficult to grind, and the raw ore feed particle size is 20mm, while the cyclone The fineness of the sand returned by the underflow of the classifier or the spiral classifier is below 60 mesh, and the particle size difference between the two is large. Closed-circuit grinding is likely to cause over-grinding of kaolinite and diaspore, or even over-grinding to <400 mesh , 70-80% of the pulp is <400 mesh, resulting in unstable production operations and indicators

Moreover, because the concentrate and tailings are too fine, the sedimentation speed is slow, and the efficiency of the filter press is low.

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