Steel manufacturing dust solidified, process for producing the same and production apparatus therefor

Abstract

This process for producing a steel manufacturing dust solidified includes placing dust (10) containing steel as a main component that occurs in a steel manufacturing process in cylindrical mold (8) and applying pressure to thereby obtain solidified dust (B). This steel manufacturing dust solidified (B) is in the form of a briquette, which has, for example, a columnar form whose cross section configuration is circular. The dimension thereof is, for example, 50 to 100 mm in diameter and 30 to 80 mm in height. The steel manufacturing dust (10) may have carbon, aluminum, etc. occurring in the steel manufacturing process mixed thereinto as a binder. The production apparatus therefor includes the mold (8), lid member (9) closing one side thereof and plunger (11) that is inserted in the mold (8).

Description

FIELD OF THE INVENTION [0001] The present invention relates to a steel manufacturing dust solidified, a manufacturing process and a manufacturing apparatus therefor, for enabling dust, occurring during an iron and steel manufacturing process with a melting furnace or the like, to be reused as a steel manufacturing raw material. BACKGROUND ART [0002] During the iron and steel manufacturing process, dry dust, which occurs as a result of coagulation of generated vapors, is generated in, for example, a melting furnace and is recovered by a dust collector. Since this dust contain iron as a principal component, the reuse thereof is desirable. However, since the iron and steel dust, when charged into the melting furnace in the form as it stands, tends to be scattered afloat and is again recovered by the dust collector, the reuse thereof is difficult. For this reason, it has hitherto been disposed by filling up in land, but the amount of generation of the iron and steel dust in Japan reache...

AI Technical Summary

Benefits of technology

[0006] An object of the present invention is to provide a steel manufacturing dust solidified, with which dust occurring during an iron and steel manufacturing process can be rendered to have an excellent handleability for reuse thereof, which does not contain excessive additives and which can be manufactured at a low cost, a manufacturing method thereof and a manufacturing apparatus therefor.

[0007] The steel manufacturing dust solidified of the present invention is a solid product formed by pressing and forming (pressure forming) a dust containing, as a principal component, iron occurring during an iron and steel manufacturing process. The pressing and forming is carried out by the use of, for example, a mold (forming die). The solid product referred to herein is in the form of a briquette, which is big as compared with the pellet that is a granulated body. Although this steel manufacturing dust solidified is desirably what only the dust occurring during the iron and steel manufacturing process (hereinafter referred to as “iron and steel dust”) is pressed and formed, it may be the dust mixed with a binder in the form of a powder of a material capable of becoming a component of the steel material, for example, mixed with a powder of carbon, aluminum or the like, that has occurred during the iron and steel manufacturing process, as a binder. The carbon contributes to increase of the thermal efficiency.

[0008] Since the steel manufacturing dust solidified of the structure described above is a big solid product as compared with what has hitherto been granulated into a pellet, after solidification, the handleability is excellent until it is charged into a furnace. Also, since it is the iron and steel dust pressed and formed and does not contain excessive additives, iron and steel manufactured by reuse can have a high quality and no gas or the like resulting from the additives will be generated. Although in the past solidification to a bigger size than the pellet in the form as it stands has been considered impossible, according to tests and a test model of the steel manufacturing dust solidified manufacturing apparatus, by properly setting pressing conditions or the like, it was possible to manufacture what has a strength generally to avoid breakage in handling even though it is a steel manufacturing dust solidified in the form of a briquette of a size greater than the pellet. If it is only the iron and steel dust pressed and formed with no binder contained therein, preparation and addition of the binder are unnecessary and, therefore, a low cost manufacture is possible. It is to be noted that if required, the binder in the form of a powder of a material capable of becoming a component of the steel material as hereinabove described, for example, a powder of carbon, aluminum or the like occurring during the iron and steel manufacturing process may be mixed in the dust as a binder for increasing the strength. With a small amount of carbon, aluminum or the like, it does not affect on reduction of the material quality of the steel material and, with the carbon, aluminum or the like occurring during the iron and steel manufacturing process, it can be available from the same steel manufacturing facility and influence on increase of the cost is minimal.

Problems solved by technology

However, since the iron and steel dust, when charged into the melting furnace in the form as it stands, tends to be scattered afloat and is again recovered by the dust collector, the reuse thereof is difficult.

For this reason, it has hitherto been disposed by filling up in land, but the amount of generation of the iron and steel dust in Japan reaches hundreds of thousand ton per year so long as an electric furnace dust is concerned and disposal by filling up in land is undesirable in terms of degradation of the environment of the land to be filled up and the effective utilization of resources.

The above described pelletizing method is such that since pellets formed are in the form of particulates of a diameter within the range of about 5 to 30 mm, a process of transporting the formed pellets into the furnace is not still efficient.

The method of filling into the container and then throwing into the furnace is costly since there is need to prepare containers that are thrown together with the dust.

However, it has hitherto been considered impossible to briquette the iron and steel dust in the form as it stand, to a strength enough to allow them to be transported and an organic binder and others are mixed to secure the strength as in the above mentioned Japanese Laid-open Patent Publication No. 2003-247026.

For this reason, not only does it contain the organic binder which is unnecessary in steel manufacture, but the addition thereof render it to be costly.

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