Blast furnace is a type of metallurgical furnace used for metal smelting and other industrial processes. It is commonly used in iron and steel making, and it is the most important metallurgical process for large-scale steel production.
The blast furnace was invented in the 19th century, and it is still used today for the production of iron from iron ore. The basic process consists of heating iron ore, carbon and other materials (such as limestone or dolomite) to a very high temperature, then reducing the ore with a reducing atmosphere. The result is a molten iron called ‘pig iron’, which can be further processed into metals such as steel.
The blast furnace is made of a cylindrical shell that is lined with refractory bricks. The top of the furnace is called the ‘bosh’, and it is where all the materials enter. Inside the furnace, there are two main chambers, the hearth and the furnace body. The hearth is where the materials are heated to a high temperature, while the furnace body is where the materials are combined to form the molten iron.
A blast of hot air is injected into the furnace through a snout. This is called the ‘hot blast’, and it is responsible for providing the necessary heat. The hot blast is usually rich in oxygen, which helps to speed up the chemical reactions taking place. As the blast travels downward, it is constantly cooled and the remaining oxygen is used up to reduce the ore.
The molten iron produced in the blast furnace is often called ‘pig iron’. This is then further refined to create different types of steel. The steelmaking process usually involves additional steps, such as adding other elements and additives, before the final product is ready for use.
In order to make the most efficient use of the blast furnace, modern plants use computers and automation systems. This allows the furnace to be constantly monitored, and any changes needed can be made quickly. Large-scale blast furnaces can be found in steel mills all over the world, and they are a key component in keeping up with the global demand for steel.
