Steel has a lot of important uses in today’s society. Stainless steel, angled bars, and deformed bars in the Philippines and all over the world have all been used to modernize the construction industry. There’s an incredibly high demand for it, and thanks to the Bessemer process, steel was able to be mass produced.

What is the Bessemer process?

The Bessemer process is the first inexpensive industrial process from the mass production of steel from molten pig iron. The main principle is to remove the impurities from the iron by oxidation with air being blown through the iron. In turn, the oxidation also raises the temperature and keeps the iron in its molten state. Everything takes place inside the Bessemer converter, a large, egg-shaped container made of steel and has a lining of clay and silica or dolomite. The capacity of the converter is from 8-30 tons of molten iron. Its narrow upper end has an opening through which the iron to be treated is poured in and the finished product goes out. The bottom has a number of perforations through which the air is forced upward in the converter during the operation. As the air passes through the molten pig iron, impurities like silicon, manganese and carbon unite with the oxygen to form oxides. The dolomite is used as lining because of its high phosphorous content. In order to provide the elements necessary to give the steel its desired properties, another substance is usually added after the oxidation is completed. Then, the converter is emptied into ladles from which the steel is poured into molds. All in all, the whole process is completed in 15 to 20 minutes.

On display along the Monongahela Riverfront in Pittsburgh.

Who came up with the Bessemer process?

Sir Henry Bessemer, an English inventor, worked on the problem of manufacturing inexpensive steel from 1850-1855. Before the Bessemer process was patented, steel was so costly that it was only used to make small things like knives, tools, and sometimes, swords. Industries used to rely on cast iron and wrought iron to make railroad systems and bridges, despite the treacherous nature of iron. There were news about cast iron beams collapsing suddenly, causing accidents, making people desperate to find material that is more durable than iron.

The Bessemer process revolutionized steel manufacture by decreasing its cost and increasing the scale and speed of production of this vital material. The process also decreased the labor requirements for steel-making. Thanks to this process, steel and cast iron became equally priced. This made users turn to steel, particularly those who are part of the railroad business. The productivity of railroads became better thanks to steel. Rails that were made of said material were ten times stronger and more durable compared to iron rails. Steel rails could also carry heavier locomotives, which could pull longer trains. Steel rail cars were also longer and were able to increase the freight to car weight from 1:1 to 2:1.

Steel production companies stopped using the Bessemer process on 1968. Although the method is obsolete already, it remains as an essential part of steel’s history. Without it, current methods of steel production may not have even come to light.