Recycling Possibilities of Metallurgical Slag

Abstract

The target of the current metallurgical industry is to recycle and utilize all their by-products. Slags are the important wastes and by-products of metallurgical industry, which have been treated, recycled and used worldwide. The present paper summarizes results obtained from physical and chemical analyses on blast furnace slag. The physical structure and gradation of granulated slag depend on the chemical composition of the slag, its temperature at the time of water quenching, and the method of production. The chemical reaction between blast furnace slag and water is slow, but it is greatly enhanced by the presence of free calcium oxide and free magnesium oxide getting on calcium and magnesium hydroxide. These alkalis can modify the mechanical properties of slag. It is very important to analyze the content of the free calcium oxide and free magnesium oxide. Blast furnace slag is mildly alkaline and exhibits a pH in solution in the range of 10 to 12. Processed slag exhibits favorable mechanical properties for aggregate use including good abrasion resistance, and high bearing strength. By our assessments it was proved that the blast furnace slag from S.C. “Arcelor Mittal Galati” S.A. have comparable properties of granite. This fact will allow utilizing the slag aggregates on the road construction, railway embankments, hydrotechnic constructions.