Briquette as material for steel making and method for production thereof

Abstract

Cotton-like aggregates (B) containing grinding chips from an iron-based metal and a grinding fluid containing oil and water are compression molded thereby forming a brittle compact (C) in which the fibrous grinding chips are roughly sheared and which is removed of excessive water and oil. The brittle compact (C) is crushed for further finely shearing the grinding chips and then, the resultant grinding chips are mixed with a solidification assistant (D) for obtaining powder (E) containing the solidification assistant (D). The powder (E) is solidified by compression molding, thereby forming a water-containing briquette (F). A briquette (A) for use as steelmaking material, which contains powdery pure iron and oil, is obtained by removing the water from the water-containing briquette (F). Without crushing the brittle compact (C), it is also possible to form the briquette (A) for use as steelmaking material by impregnating the brittle compact (C) with the solidification assistant (D) and then drying th compact.

Description

Technical Field[0001] The present invention relates to a briquette for use as steelmaking material and a method for forming the same and more particularly to a technique for effectively utilizing grinding chips from an iron-based metal.BACKGROUND ARTS[0002] Grinding chips which occur in the machining of an iron-based metal such as bearing steel, carburized steel and the like (hereinafter, the term "machining" will be used to represent a concept also including grinding, super-finishing grinding, lapping and the like) are recovered in the form of cotton-like (fibrous) aggregates including a grinding fluid containing water and oil, abrasive grains, and the like. Since the cotton-like aggregates contain a considerable quantity of pure iron, there have been made attempts to reuse the aggregates as steelmaking material. Unfortunately, however, the cotton-like aggregates contain such a large quantity of water that bumping (phreatic explosion) will be caused by the water if the aggregates a...

AI Technical Summary

Problems solved by technology

Unfortunately, however, the cotton-like aggregates contain such a large quantity of water that bumping (phreatic explosion) will be caused by the water if the aggregates are directly charged into a blast furnace.

The use of a reducing agent results in increased costs.

On the other hand, the grinding chips with the oil adhered thereto are prone to adhered to each other.

Hence, the compression molding of the cotton-like aggregates involves difficulty about accomplishing solidification to a desired strength.

Furthermore, in the case of cotton-like aggregates containing a large quantity of grinding chips from an iron-based metal containing not less than 0.2 wt % of carbon, the aggregates present such a great springback when compressed that it is difficult to accomplish the solidification to a desired strength by compression molding the aggregates.

In addition, the fibrous grinding chips contained in the cotton-like aggregates a...

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