Dry processing technique for iron-containing steel slag

Abstract

The invention discloses a dry processing technique for iron-containing steel slag. The technique comprises the following steps: iron-containing steel slag powder is passed in a rotary drum dryer for drying, then is passed in a ball mill for dry milling, and is passed in a powder concentrator for classifying to two particle stages of more than 0.045 mm and not more than 0.045 mm; fine powder with particle size not more than 0.045 mm is collected by a dust collector to obtain steel slag micro-powder; coarse powder with particle size more than 0.045 mm is magnetically separated by a dry permanent magnetic drum magnetic separator to classify into a magnetic containing material and a nonmagnetic containing material; the nonmagnetic containing material is directly returned to the mill for regrinding; and the magnetic containing material is separated to obtain steel particles with particle size more than 0.9 mm and iron flavor powder with particle size not more than 0.9 mm. The technique has the benefits that such iron resources as the iron flavor powder and the steel particles are effectively extracted from the steel slag, building material products, actually the steel slag micro-powder, are obtained, any waste slag is not generated, the water pollution is not produced, and the land resources are not occupied; and the technique has the advantages of simplicity, low investment, low energy consumption, energy conservation and environmental friendliness.

Description

technical field [0001] The invention belongs to the technical field of steel slag treatment, and in particular relates to a dry treatment process for iron-containing steel slag. Background technique [0002] my country's iron and steel companies discharge nearly 100 million tons of steel slag every year. Steel mills generally undergo magnetic separation and crushing, and after recycling large pieces of slag and iron, three products are produced: slag steel, magnetic materials, and non-magnetic materials. Among them, the magnetic material accounts for about 20%, the iron content is 15-35%, and the particle size is 0-30mm. We call it high-speed iron slag powder. There are also 0-3% metallic iron in non-magnetic materials. [0003] In order to effectively recover the iron resources in the slag, all steel mills are currently attaching great importance to the treatment of high-iron steel slag. The main treatment method is to use wet grinding and magnetic separation technology. T...

AI Technical Summary

Problems solved by technology

However, the current main treatment and utilization methods of steel slag are still extensive and low value-added treatment and utilization.

There are the following deficiencies: (1) The system is complex, the operation is difficult, the labor intensity is high, the equipment investment is high, and the floor area is large; (2) The tailings produced by water separation are still wrapped with some metallic iron due to the large particles, and there is iron Waste of resources; (3) The sludge produced by water separation is extremely fine, high in moisture, and high in viscosity, and the treatment method is extensive and difficult

There is no mature treatment method at present, and it is generally used for landfill or dumping, which not only occupies a large amount of good land resources, but also has obvious waste of resources

(4) Because the processing technology is inseparable from water, the waste of water resources is serious. At the same time, some heavy metals in steel slag accumulate too much and infiltrate into groundwater sources, which will pollute groundwater resources.

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