RU2688789C2 - Slag processing method - Google Patents

Abstract

FIELD: metallurgy.SUBSTANCE: invention relates to metallurgy, namely to slag processing methods for production of raw material with high iron content. Fine iron with fraction of not more than 50 mm with total iron content of more than 70 % is obtained by loading iron-containing slag into rotor crusher from height, which provides required speed of its entry into crusher due to free fall. Crushing of slag in rotary crusher is carried out with linear rotation speed of beam of not less than 40 m/s. Thereafter, the product is repeatedly divided into fractions by magnetic separation.EFFECT: method provides higher percentage of iron in end product and higher capacity of slag processing.1 cl, 1 dwg

Description

The invention relates to the field of metallurgy, and in particular to methods of processing slag to obtain raw materials with high iron content.

The closest analogue of the claimed invention is a technical solution from patent RU 2511556. The method includes pre-screening with the release of oversized pieces, separation with the release of metal concentrate, crushing slag, screening, additional crushing and magnetic separation with the release of magnetic and non-magnetic products. Slag crushing is carried out to a fraction of -10.0 + 0.0 mm, followed by sieving into three fractions: -10.0 + 1.0 mm, -1.0 + 0.315 mm and -0.315 + 0.0 mm. The fraction -10.0 + 1.0 mm is subjected to additional crushing and returned to screening. Each of the two fractions: -1.0 + 0.315 mm and -0.315 + 0.0 mm separately dried. Then, the two separated streams are first subjected to electroseparation with separation into conductor and non-conductor fractions. Each of the obtained fractions is sequentially subjected first to weakly magnetic and then strongly magnetic separation with the release of a strongly magnetic fraction in the form of iron scrap and coarse and fine fractions of the metal phase of ferroalloys and the release of a nonmagnetic non-conductive fraction in the form of high-alumina concentrate.

However, this method involves multi-cycle grinding, which increases the time of the operation, resource and complexity of the process.

The technical problem to which the invention is directed, lies in the low efficiency of existing slag treatment methods with the aim of producing metallic iron.

The technical result of the claimed invention is to increase the percentage of iron in the final product while increasing the productivity of processing.

This technical result is achieved due to the fact that in the slag processing method, iron-containing slag is crushed in a rotary crusher with a linear rotation speed of at least 40 m / s, after which magnetic separation is carried out.

In the method can be used rotary crusher with a vertical shaft of rotation.

After magnetic separation can carry out the separation into fractions.

After separation into fractions, additional magnetic separation can be carried out followed by separation into fractions.

The invention is illustrated by the figure, which shows a family of experimental graphs of the percentage of Fe-iron in the extracted (final product) from the speed of rotation hit.

The method is as follows.

To obtain an iron-containing product of the required quality, single-cycle continuous crushing in a rotary crusher, for example, with a vertical shaft, with a linear speed of rotation of 40 m / s and above, is used. At such a speed of impact, most slag formations are destroyed due to their own fragility without destroying pieces and iron particles that do not crumble or crush due to their plasticity, thereby increasing the percentage of iron in the final product.

The time of slag crushing is determined by the length of time associated with the passage of slag in free fall through the impact zone, ie tool destruction. To increase the rate of passage of the product through the crusher, you can load into the crusher from a certain height, providing the necessary speed of entry of the product into the crusher due to free fall.

For crushing, high-performance special crushers are used, allowing with a large mechanical power to act on raw materials-slag, in particular, rotary crushers with a vertical shaft of rotation, allowing to get speeds of more than 100 m / s and maintaining their working capacity. For example, a rotor crusher can be used in accordance with patent RU 2305007.

At the exit of the crusher, a strongly crushed iron-containing product of a fraction of 0-50 mm is obtained. Next, the crushed product undergoes repeated separation into fractions (sieving) with magnetic separation and receive fine iron (MJ).

For magnetic separation and screening by fractions of the resulting product, you can use any standard device that provides the necessary performance and composition of the output product MJ. At the outlet of the magnetic separator, an iron-containing product is obtained with the desired total Fe content, i.e. Fe-metallic and FeO- in oxides.

The inventive method provides in-depth processing of solid slag waste from metallurgical production, which results in a new type of product (raw material) for metallurgical production, characterized by a particle size of from 0 to 50 mm with a total total iron content of more than 70% and called fine iron.

A feature of this method of processing iron-containing slags is the direct dependence of the depth of extraction of iron from slag and the resulting value of total iron in the product at the output of the linear velocity. The beginning of the effective slag processing is the linear velocity of 40 m / s of the impact of the beat. With a further linear increase in the speed of the beat, the indicators of the depth of iron extraction from slag increase with a simultaneous increase in the total iron content in the resulting MJ product. By selecting the required linear velocity in the range of 40 m / s and more, the desired iron extraction from steelmaking slag and the quality of the fine iron product (MJ) can be obtained.

The inventive method allows both extracting and extracting additional Fe-metal from the slag and additional volume in oxides in oxides, as well as improving the quality of iron-containing waste to the quality required by the technology and improving the quality of already-existing iron-containing waste.

The examples are special cases and do not exhaust all possible implementations of the claimed invention.

It should be clear to a person skilled in the art that various variations of the proposed method do not change the essence of the invention, but only determine its specific embodiments.

Claims (2)

1. A method of producing fine iron with a fraction of not more than 50 mm with a total iron content of more than 70%, characterized in that the iron-containing slag is loaded into a rotary crusher from a height that provides the necessary speed of its entry into the crusher due to free fall, the subsequent crushing of slag into rotary crusher with a linear speed of rotation beat at least 40 m / s and multiple separation of the product into fractions with magnetic separation. 2. The method according to p. 1, characterized in that use a rotary crusher with a vertical shaft.

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