A blast furnace is used in the smelting of iron.
Blast furnaces are devices used in the iron smelting process. The heat generated in the furnace allows iron to be produced from iron oxide ores. A blow of air contained in the blast furnace itself helps to intensify the degree of heat, speeding up the smelting process.
In appearance, the typical blast furnace is tower-shaped. Safety doors are mounted on the front of the device, allowing the raw material to be introduced into the oven manually or by means of a conveyor belt. Some furnaces of this type are also equipped with a bottom drawer that makes it much easier to collect slag and other finished products.
Furnaces of this type are often used in the steelmaking process. A blast furnace is ideal for combining coal and iron ore. The extreme heat of this type of furnace allows both substances to melt into an integrated liquid metal that forms what is known as pig iron. The pig iron is removed from the furnace base from time to time and is used in the creation of many different types of building materials.
Along with coal and iron ore, limestone or some other type of flux can also be introduced into the mix. The kiln tower design makes it very easy to control the degree of heat generated in the main chamber, allowing the operator to temper raw materials as needed. Although many aspects of the steel industry have benefited from modern technology, the basic design and operation of the blast furnace have remained largely unchanged for centuries, because it remains the most economical way to produce iron on a large scale.
The origin of the blast furnace is generally traced to China during the 5th century BC. In the Middle Ages, the use of this type of oven was found in England, as well as in parts of Europe. The device’s current design is often attributed to several early 18th-century innovators who refined the blast furnace’s ability to produce large quantities of product in a single sitting. At the same time, this latest design also allows the blast furnace gas produced by the release of carbon monoxide from charcoal to be used as a reducing agent for the pig iron created in the furnace.
Furnaces of this type remain an important part of the steelmaking process throughout the world. Relatively inexpensive to operate and maintain, a blast furnace can last for generations before needing to be replaced. Furnace profitability helps ensure that steelmakers can remain competitive in today’s world, even as metals produced by other methods become difficult to sell.