Basic Overview of Blast Furnace Materials
Blast furnaces are used in the steel production process to convert iron ore into high-grade steel. The components of the furnace – the frame and tuyeres are usually made of steel, while the refractory lining is constructed of materials that can withstand the furnace’s extreme temperatures. Steel is produced when iron ores, in combination with coke fuel and limestone, are heated to temperatures in the range of 2,600–3,000 degrees Fahrenheit.
Types of Blast Furnace Materials
Refractory materials are the basis for the protection provided by blast furnace walls and linings. Depending on their construction, many refractory materials are capable of withstanding extremely high temperatures and are suitable for a variety of applications. Refractory materials commonly used in blast furnaces include basic refractory materials, such as alumina, alumina-silicate, carbon, and magnesia.
The main types of basic refractory materials used for lining blast furnaces consist of alumina (which can resist temperatures up to 3,600°F), alumina-silicate (which can resist temperatures up to 3,200°F), magnesia (which can resist temperatures up to 2,400°F) and carbon (which can resist temperatures up to 2,200°F).
In order to construct an entire blast furnace, other important components and materials will also be needed. These include ceramic anchors, welded anchors, fire-resistant and non-metallic components, graphite filled and lubricant-filled materials, flame-resistant insulation materials, and lining materials.
Coke
Coke is a fundamental material in the steel production process. It is made from coking coal which is produced from low-ash and low-sulfur bituminous coal. Coke is used as a fuel in blast furnaces and, due to its higher carbon content and higher energy content, produces more heat than coal. It is also used as a reducing agent, to reduce iron ore to the liquid iron needed for steel production.
Limestone
Limestone is a sedimentary rock composed primarily of calcium carbonate. It is used in the production of blast furnaces primarily because it acts as an essential flux agent. It helps to reduce the melting temperature of the iron ore, which makes the process of producing steel faster and more efficient.
The Use of Iron Ore, Coke and Limestone
In order to produce high-grade steel, iron ore, coke and limestone are combined and heated together in a blast furnace. The iron ore is the major component in the furnace, with limestone and coke acting as fuel sources and flux agents, respectively. The heat generated in the furnace reduces the iron ore, coalescing it into liquid iron. As the iron liquid cools, it becomes molten steel, which is then channeled into molds and cooled to produce steel of different shapes and sizes.
Conclusion
Blast furnaces are essential components in the steel production process. Refractory materials are the basis for the protection provided by blast furnace walls and linings and important components needed for construction. Coke, limestone, and iron ore are also necessary for the operation and production of high-grade steel.
