A method and device for dry grinding and separation of magnetite

Abstract

The invention discloses a magnetite dry grinding and dry separation method and a magnetite dry grinding and dry separation device, and belongs to the technical field of iron ore selection and grinding. The method comprises the steps of mixing secondarily crushed ore with particle size less than 80mm and coarse-grain return scrap to obtain a mixture I, extruding the mixture I by virtue of a high pressure roller, and mechanically screening the mixture I, wherein the screening granularity is 3mm; returning an oversize product adopted as the coarse-grain return scrap to the high pressure roller to be continuously extruded, separating screen underflow in a dry-type magnetic separator, grading rough concentrate separated by the dry-type magnetic separator by virtue of a wind power powder separation machine, returning coarse powder graded by the wind power powder separation machine and adopted as coarse-grain return scrap to the high pressure roller to be continuously extruded, collecting fine powder meeting the fineness requirement of iron fine powder after the grading of the wind power powder separation machine, separating the fine powder by virtue of the dry-type magnetic separator, and finally carrying out the wet-type magnetic separation for fine magnetic minerals meeting the fineness requirement of the iron fine powder after the separation of the dry-type magnetic separator. By adopting the magnetite dry grinding and dry separation method, the crushing grinding and the magnetic separation of the ore are reasonably matched, so that the system energy consumption is reduced, consumption of steel and water is reduced, and the environmental pollution is alleviated.

Description

Technical field [0001] The invention belongs to the technical field of iron ore beneficiation and grinding. Background technique [0002] In the magnetite beneficiation industry, the preparation of iron concentrate needs to reach a certain grade and fineness. In the process of gradually thinning the raw iron ore and improving the grade, the magnetic separation efficiency is obviously related to the iron ore particle size. , and to achieve a certain particle size requires corresponding work and energy consumption. Considering the maximization of economic benefits, it is necessary to reasonably select the ore particle size corresponding to each level of magnetic separation. Traditional crushing and grinding are mainly completed by crushers and tube mills. Since the crusher is limited by equipment performance and power consumption, it can only proceed to the fine crushing stage (generally crushed to <12mm), and then the tube mill completes the coarse grinding process. Grind...

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Problems solved by technology

The tube mill has high power consumption and steel consumption, and the general fine grinding adopts wet ball mill, which consumes a lot of water, the cost of tailings treatment is high, and it has great environmental pollution

In recent years, some technologies have also introduced high-pressure roller mills into the iron ore grinding system, but only replaced part of the fine crushing and coarse grinding, and solved the problem that the large particle size of the crusher affects the efficiency of magnetic separation, but the high-pressure roller The material after grinding by the mill needs to be finely ground by the tube mill, which has not fully solved the problems of high energy consumption and large water consumption of the tube mill

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