From The Impure Haematite To Steel – How Steel Is Produced?

Steel, a fantastic metal structure, requires a lot of effort and resources to produce. However, like anything good in this world, steel is undoubtedly worth the effort so let’s take a look at how steel is produced!

From Haematite To Iron:

After harvesting iron ore(haematite) from the mines, crude iron goes to the blast furnace. The blast furnace is an oven shaped like a chimney and running at least 30 meters tall. A mixture of iron ore, limestone, and coke is placed on the roof of the furnace.

At the bottom, hot air blows in, increasing the temperature to blazing 1400 Celsius. At such a high temperature, coke (carbon) burns off to produce carbon monoxide. The release of carbon monoxide marks the start of real iron extraction. The gas reacts with the ore to give back molten iron, which then trickles down to the furnace’s bottom.

However, silica still remains a major impurity in the molten iron. This is where limestone comes into play; extreme heat decomposes limestone into calcium oxide and a gas. The calcium oxide reacts with silica to form a slag, which is lighter than iron, so it floats on the surface of liquid iron. Then the molten iron is slowly tapped out from the bottom.

Where Next?

What comes out of the furnace is still an impure form of iron called pig iron. Pig iron contains carbon and sand as primary forms of impurities, so it’s poured into another furnace called an oxygen furnace. A jet of pure oxygen forced into the furnace reacts with carbon to give off carbon monoxide. Oxygen also reacts with other impurities to form acidic oxides. Again to combat sand, limestone is used, which converts sand into slug. The slug is then scooped from the surface, leaving behind the purest form of iron.

However, pure iron is of no good use in the construction industry. Pure iron is very soft and deforms easily. Even worse, it rusts very quickly. On the contrary, the addition of some carbon turns the weak iron into robust steel. Hence, carbon is re-administered into the molten iron, but in controlled amounts. Too much carbon content will yield a brittle and difficult to weld steel, so controlling carbon input is essential.

Along with carbon, engineers add a few other elements, such as nickel and chromium. Such additions result in different specified categories of steel, such as stainless steel. The obtained molten steel is then poured into molds, where it cools into its new shape.

Conclusion:

From the impure ore to our beloved steel, iron has to journey through two burning hot furnaces. The result is worth the effort as steel makes up most of the macrostructure of our modern world. The steel’s immense uses, types, and convenience it provides makes us its fan. Hence, Fort Bend Steel Supply has gathered an extensive collection of steel products. Feel free to surf through our collection. For more inquiries and information, you can call us at: 281-499-5800.

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