Steel first became known to man in the 17th Century in England. The process used was called cementation, whereby the Vikings increased the carbon content in molten iron.
Few fireworks displays are more spectacular than in the process of making steel. The story of hot metal and steel is fascinating from the start from finish.
The story begins with a blast.
It starts with the mining of the iron-ore. As rock explodes and the steel raw materials blasted from the ground. The rock blasted is Taconite. Taconite is a form of iron formation beneath the earth which contains crude iron-ore.
2. Conversion to steel
The rock is then ground into powder by powerful industrial grinders. The ground materials then passed through powerful magnets that attract the ore pellets from the mixture.
The ore is then heated into marble-sized pellets to be converted to iron. Electrodes and natural gas burners do the heating. The metal is then crushed, sealed into tight air ovens and baked for 12 – 16 hours. Limestone is then added to remove the impurities while still heating the mixture continuously by heated air to change the material into molten iron.
At regular intervals, the blistering brew heats giant ladles where iron turns to steel. High purity oxygen is then blown into the mixture at supersonic speeds converting molten metal into molten steel. This process generates a spectacular show of fireworks as oxygen adds to the molten metal. The procedure of blowing high purity oxygen is done to reduce the carbon content of the molten steel and speeds up the melting process.
3. Forming and finishing.
A funnel placed below a massive ladle feeds a continuous caster containing moulds that form the molten steel in the shapes desired. The molten steel at 3000 degrees Fahrenheit then cools to a red hot solid. The profile of the moulds determines the figure of the semi-finished product coming out of the caster.
The product that comes out from the caster is made of slabs of up to 40 feet long. They are then stacked into a storage area to await further processing.
4. Hot strip mill
In hot strip mills, slabs transform into different steel bars and sheets. The blocks are again heated to 2400 degrees Fahrenheit and decaled into the various sizes as desired. The whole process is often automated and happens without human intervention.
The finished products may be angle iron, steel channel, strip and flat bars, UM plates, wide flange beams, standard I-beams, pipes, square tubings, plates, sheets, floor plates, hex bars, expanded metal, pipe fittings and other products.
These are products then used in building of the magnificent skyscrapers and towers that we love, not forgetting the floating bridges connecting different parts of the world.