Steel slag is the solid waste generated from steel smelting processes and is mainly composed of iron oxide, silicon oxide, calcium oxide, carbon oxide, silicon oxide and other salts. Steel slag is a kind of industrial solid waste. In the process of iron and steel smelting, iron-containing solid materials and non-ferrous metals are used as fluxes and ore materials, which form oxides, slag and reduce their volume. After a series of physical and chemical reactions in the smelting process, finally, a certain amount of steel slag is generated. This is a by-product of steel production.
Steel slag has typical physical and chemical properties, which is beneficial to the production of cement-based materials, such as cement admixtures, concrete admixtures and pavement materials. Compared with natural stone, it has the advantages of reducing production cost and more features such as good strength and elasticity.
Steel slag can be used in metallurgy, raw material cement production and production of stainless steel and other steel products. It is also an ideal raw material for sand blasting, ceramic tile and asphalt pavement production. Not only can it improve the quality, but it can also reduce environmental pollution and running costs.
At present, most steel slag is used for producing concrete admixture, cement production and highway pavement materials. Steel slag, compatible with ordinary Portland cement, has greater strength and durability than ordinary limestone aggregate. Its texture is smooth, fully combining with cement, making it an ideal material for producing concrete admixtures and other cement-based admixtures.
For cement production and highway pavement materials, steel slag has advantages of low price and performance, simple production process and less use of manual labor. Steel slag admixture for Portland cement increases the strength of concrete. Steel slag can replace natural sand to produce concrete and asphalt pavement materials, making them more durable and economical.
In view of the advantages of steel slag, many countries are increasing their utilization rate and paying more attention to it. However, the lack of common international standards has become the biggest obstacle to promoting steel slag utilization. Different standards and different evaluation methods lead to uneven market prices.
It is hoped that governments at all levels can introduce more national standards, and combine advanced steel slag recycling and utilization technology with actual enterprises, while providing more use guidance and support. Relevant departments should also promote the building materials industry to increase the use of steel slag and gradually green the steel slag industry.
