Raw materials in the Steel Industry

In this 21^st century, the steel industry is one of the most pioneering industries for mankind, with applications ranging from the precision tools in the medical industry, to the reinforcement bars that strengthen our homes. The quality and processing of the raw materials, required by specific industries, determine the quality and value of the final steel product. These raw materials also need a system of heavy machineries that process the material at every step of the way.

• Iron ore: It is found in the Earth’s crust, in its oxidized form, as magnetite (Fe₃O₄, 72.4% Fe), hematite (Fe₂O₃, 69.9% Fe, etc. These compounds contain high iron content per unit mass, and can directly be fed into a blast furnace for further mechanisms. Approximately 1.5 tonnes of iron ore is processed, to make 1 ton of pig-iron. Pig iron is later processed, to form steel billets, by heating in arc furnaces. Iron ore serves as the primary raw material for manufacturing a wide range of steel products.
•  Coal/Coke: Bituminous coal is heated at 1000-2000 °C in a blast furnace, to drive off impurities, leaving nearly pure carbon. The furnace is blasted with a hot blast of combustion gases, producing softened liquid, which is cooled with air/water to form porous lumps of ‘coke’. Coke is used as a reducing agent, which reacts with the oxygen released from the ore, separating pure molten iron. This iron is further alloyed with various elements, to form a range of steel products.
•  Fuel gases: A vast number of fuel gases are incorporated in the steel industries. Right from the blast furnace gas used for pre-heating, to acetylene torches, that cut the steel billets. They include Production gas, Natural gas, LPG, acetylene, coke oven gas, blast furnace gas, converter gas, etc. These gases are combusted and burned as fuels, that provide the heating element throughout the machineries. Their flammability, flashpoints, and other chemical properties affect their preference in usage, in a variety of processes.
• Flux and Alloying elements: The coke and iron ore, is combined with the flux materials like limestone, dolomite, etc. and supplied to the furnace. The flux is used to remove the impurities like silica, phosphorous oxides, nitrogen, silicon, phosphorus, sulfur, and excess carbon. Alloying elements such aluminium, chromium, cobalt, copper, lead, manganese, molybdenum, nickel, tin, tungsten, zinc, vanadium, etc.are further added, to produce different grades of steel. The quality of these components, determine the consistency of crystalline lattice composition of the alloy.

With the constant development of the scientific technologies, that improve the quality of manufacturing steel products, India is emerging to be a global superpower in steel exports. Due to high domestic consumption, which has been fostered by the Indian Government, and humongous exports, steel has been contributing to the developing economy of our country. The high quality of raw materials used, thus results in the pristine quality of the resulting products. Agni Steels is a proud manufacturer of high-quality TMT Steel bars, that are shaping the constructions of tomorrow.