Method for purifying granular slag steel

Abstract

The invention relates to a purifying method for a particle type slag steel, wherein, an autogenous tumbling mill is used to mill without media the particle type slag steel that is weathered, smoldered and in particle size >60 mm, TFe>50%, and an semi-autogenous tumbling mill is used to mill with media the particle type slag steel that is weathered, smoldered and in particle size 30-60 mm, TFe 30 swung dash 50%. During the milling, the non magnetic slag and small steel particles attached on the slag steel surfaces separate from the substrates due to the bumping and rubbing between the milling body and the raw materials, and between the raw materials. After being discharged from the mills, the raw materials smaller than 30 mm are sieved away to obtain class A slag steel with TFe>=90% and class B slag steel with TFe>=80%. The invention has the advantages of the compact structure, the small footprint, the no waste water, waste slag and waste gas discharging and the no dust flying during the production, and the realization of clean production while realizing hi-efficiency use of steel slag resources. The class A/B slag steel sieved from the particle slag steel can be directly used by steel and iron making plants.

Description

【Technical field】 [0001] The invention relates to a purification method, in particular to a method for purifying low-grade granular slag steel by using a dry autogenous mill or a semi-autogenous mill. 【Background technique】 [0002] my country's steel output has exceeded 400 million tons, and the production of steel slag has also exceeded 100 million tons. The development and utilization of steel slag resources is an important measure to realize the comprehensive utilization of metallurgical slag resources. The industrial policy in terms of platooning has significant economic and social benefits, and it is of great significance to ensure the sustainable development of the steel industry. [0003] In order to maximize the recovery of metallic iron in steel slag, some iron and steel plants pile up steel slag in the open air, and use artificial water spraying method to make the steel slag weathered naturally, so as to realize the separation of metal and slag; more and more iron ...

AI Technical Summary

Problems solved by technology

[0004] In order to further improve the grade of steel slag, most domestic iron and steel mills use the ball mill washing process to purify the above two kinds of granular slag steel, but the disadvantages of this process are: first, the grain size difference of slag steel is large, and the large and small materials are clearly classified during ball mill water washing , so that the non-magnetic slag attached to the surface of the small-grained slag steel is difficult to remove, and the efficiency is low; second, the metal content in the tailing slag is still as high as about 20%, and its water content is higher than 30%, which is not conducive to further enrichment; The land area is too large, and its water treatment system is complicated and inefficient; fourth, the waste slurry is difficult to handle, causing serious pollution to the surrounding environment, causing serious waste of water resources, and making it difficult to recycle non-magnetic steel slag, and energy consumption Increase

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