What is a blast furnace?

A blast furnace is a construction designed to convert iron oxide into pure, molten iron through the application of heat and the presence of flux and coke. The furnace itself is a tall stack, often constructed from steel. At the bottom is an air heater and pump, which sends hot air into the stack in order to facilitate the numerous chemical reactions needed to convert the impure oxide into iron.

How Does a Blast Furnace Work?

A blast furnace uses heat to convert iron oxides into liquid iron, which can then be used for a variety of industrial applications. The blast furnace is a brick-lined, stainless steel stack, which is heated using pre-heated air. Limestone, coke and iron ore are placed in the blast furnace and heated. The coke, limestone and iron react in the presence of heat, producing slag and liquid iron. These liquids are then drained away and utilized elsewhere.

What Are the Advantages and Disadvantages of a Blast Furnace?

The main advantages of a blast furnace are that it is a cost-effective method of producing iron and steel, far cheaper than other methods. If done correctly, it can also be an opportunity to create energy. Blast furnace activity is also a continuous process, enabling large amounts of iron oxide to be transformed into pure, molten iron in a relatively short space of time. It also means that blast furnaces are relatively straight-forward to automate, creating further cost savings.


The disadvantages of blast furnaces is that they consume a considerable amount of energy and that sometimes it can be difficult to source the correct type of materials to use in the blast furnace in order to get the required results.