Low-quality raw bauxite ore open-grinding and dressing technology

Abstract

The invention provides a low-quality raw bauxite ore open-grinding and dressing technology. The technology comprises the following steps of roughing, scavenging and selecting so as to obtain concentrate with A/S of 5.6-6; feeding the bottom flow or return sand discharged by a classifying machine into another grinding machine for grinding and then classifying by another classifying machine, wherein the A/S of the bottom flow or return sand achieves the middle-quality bauxite standard, and the ore granularity is less than 60 meshes; roughing, scavenging and selecting overflow in which the ore with granularity less than 200 meshes accounts for +/-95% so as to obtain concentrate with A/S of 8-11. By fully utilizing the difference in Mohs hardness of diaspore and kaolinite, the technology improves A/S of bauxite concentrate to 8 above, can improve the production of alumina, and is high in Al2O3 recovery rate, energy-saving, low in cost and low in alkaline consumption; for ore dressing enterprises, the technology can increase the yield, save energy and reduce the cost, has favorable quality and price, and generates great benefit; the technology can also be used for producing in high-aluminum clay ore dressing enterprises; the technology can be used for dressing middle-grade bauxite, and the A/S of the concentrate 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), which is 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 overfl...

AI Technical Summary

Problems solved by technology

[0004] At present, the biggest problem with the closed-circuit grinding process is that it does not take into account 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 , the pulp of <400 mesh accounts for 70-80%, resulting in too fine concentrate and tailings, slow settling speed, and low efficiency of filter press

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