Embedded-type all-grain-size dry magnetic separation technology for closed recycle of iron-containing minerals in steel slag

Abstract

The invention discloses an embedded-type all-grain-size dry magnetic separation technology for closed recycle of iron-containing minerals in steel slag. The technology mainly comprises modified treatment of the steel slag, treatment of coarse-grain steel slag, treatment of medium-grain steel slag and treatment of fine-grain steel slag. Specifically, when a steel furnace pours the steel slag, with utilization of the heat of the steel slag, lignite is added to serve as a reduction modifier so as to improve the magnetic property of the iron-containing minerals in the steel slag; and the modified steel slag is subjected to two times of crushing by a jaw crusher and enters a high-pressure roller mill for intermediate crushing after the iron-containing minerals in the steel slag are recycled by magnetic separation of a single-roller magnetic separator, the steel slag after the intermediate crushing enters a ball grinder twice for grinding, and according to the separation effect of the steel slag and a separation requirement of the magnetic separator, the optimal granularity range is 0.1 mm to 0.3 mm. According to the dry magnetic separation technology, efficient separation of different steel slag with coarse, medium and fine grains can be achieved, the magnetic separation technology is optimized, the dry magnetic separation technology for multiple products has higher market competitiveness, and meanwhile, the technology is energy-saving and environment-friendly, thereby according with relevant national policies.

Description

technical field [0001] The invention relates to a steel slag treatment process, specifically an embedded full-grain closed-circuit recovery steel slag iron-containing mineral dry magnetic separation process, which belongs to the technical field of ore dressing and resource comprehensive utilization. Background technique [0002] Steel slag is the waste slag discharged during the steelmaking process. In addition to the existing 400 million tons, its stacking volume is increasing at a rate of 80-90 million tons per year. It not only occupies a large amount of cultivated land, seriously pollutes the environment, but also causes the loss of iron resources in steel slag. The comprehensive utilization of steel slag includes recycling steel scrap from converter steel slag, using tailing slag in building materials (such as brick making and cement making), as sinter flux, as agricultural fertilizer and acidic soil improver, and in the preparation of glass ceramics. At present, the ut...

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Problems solved by technology

However, due to the different magnetic properties and serious inclusions of iron-containing minerals in fine-grained steel slag, the existing magnetic separation equipment in steel plants is mostly single-separation and the magnetic system is a single-ring magnetic system, which cannot meet the requirements of the same separation and separation of minerals. Due to the requirements of the magnetic flipping process, it is imperative to use new magnetic separation equipment to achieve effective separation of fine-grained steel slag; and because of the existing processing technology, in order to meet the particle size requirements of fine-grained steel slag separation, it must be equipped with With ball mill as the main grinding equipment

Then, in the process of grinding steel slag, it is inevitable to produce powdery minerals with high hardness and poor grindability index. If they are returned to the ball mill for secondary use, because of the repeated enrichment of refractory minerals It will increase the power consumption of the mill and reduce the service life of the mill

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