From Iron Ore to Steel — A Detailed Description Of How Steel Is Made
Introduction
Since the invention of steel, it has become a mainstay of the construction industry in Atlanta and all around the world, finding extensive usage in construction of skyscrapers and reinforcement of buildings.
Steel is made of iron which is processed from iron ore found naturally on earth.
Steel is very strong and highly durable, but since it is made of iron, steel exhibits some of the properties of iron such as susceptibility to corrosion when exposed to air. That is why steel suppliers in Atlanta generally manufacture galvanized steel, which is commonly known as “stainless steel” to make it corrosion-proof.
Making and Processing Iron
Iron occurs naturally in form of iron ores. These ores are hauled from iron mines and transported to a foundry (a factory for smelting and making iron). Iron ores occur inside rocks; so they are first ground into fine particles and mixed with coke (pure coal with high carbon content) to form a coarse material called sinter.
The sinter is then mixed with more coke along with limestone and put in a blast furnace. A blast furnace is a brick structure that heats the mixture up to 3600 degree Fahrenheit via hot air. The temperature burns the coke to produce carbon monoxide, converting iron ore to raw molten iron.
The molten iron is then collected from the bottom of the furnace, which is solidified for making iron products.
Making Steel
For making steel, the molten iron formed in the furnace is further treated with additional materials. Steel suppliers in Atlanta use either of the two methods mentioned below for making steel:
- Basic Oxygen Furnace:
Molten iron is heated with about 3 to 4 times as much iron in a blast furnace. Oxygen gas is normally used to remove impurities from the molten mixture. Lime is then added that reacts with contaminants such as silicon and manganese to form slag.
Carbon, which comes from coke, forms carbon monoxide on reaction with oxygen and converts molten iron to steel. The molten steel is then removed from the furnace and poured into pre-made casts to give it the required shape and size.
2. Electric Arc Furnace:
A special furnace is used for this process. Instead of heating with hot air, the iron is melted using electricity from electrodes. The difference between this and the oxygen furnace method is the source of heat required for melting the iron.
Casting
Molten steel is immediately poured into casts to give it the desired dimensions. After the steel solidifies, the casts are removed to reveal the final product. Steel can also be galvanized further to give it additional protection from corrosion.
