What is the use of blast furnace slag?

Blast furnace slag is an industrial solid waste. The slag discharged during the ironmaking process of a blast furnace, also known as blast furnace slag, can be divided into steelmaking pig iron slag, casting pig iron slag, manganese iron slag, etc. In some regions of China and the Soviet Union, titanium magnetite is used for ironmaking to discharge vanadium titanium blast furnace slag. Depending on the grade of the ore, 0.3-1 ton of slag is discharged for each ton of iron produced. The lower the grade of the ore, the greater the amount of slag discharged.

Blast furnace slag is a solid waste formed from gangue in ore, ash in fuel, and non-volatile components in solvents (usually limestone) during the ironmaking process in blast furnaces. It mainly contains oxides of calcium, silicon, aluminum, magnesium, and iron, as well as a small amount of sulfides.

In China, slag and crushed stone can replace natural stone materials for highways, airports, foundation engineering, railway ballast, concrete aggregates, and asphalt pavements. It can be used to prepare slag and crushed stone concrete, apply it in weak foundations, and pave asphalt pavements with slag and crushed stone as the base material. The asphalt pavement is not only bright and has good anti slip performance, but also has good wear resistance. The braking distance is shortened, and when used for railway ballast, it can appropriately absorb the vibration and noise generated by trains during operation. Expanded slag bead is a kind of porous light slag formed by quenching high slag slag with proper amount of cooling water. The production methods include spray method, spray method, trench cutting method and drum method. It can be used to make lightweight aggregates, for making interior wall panels, floor slabs, etc., and can also be used for load-bearing structures. Blast furnace slag can also be used to produce slag wool (a white cotton like mineral fiber obtained by melting blast furnace slag as the main raw material in a melting furnace and refining it), microcrystalline glass, silicon calcium slag fertilizer, slag cast stone, hot cast slag, etc.