Making Iron & Steel

The two main basic processes at Bilston were ironmaking and steelmaking. For those unfamiliar with how this was done I have shown two diagrams below…

Worldwide, Ironmaking today is still very much carried out using the blast furnace – this has not fundamentally changed. On the other hand steelmaking has and the Open Hearth process is more or less completely phased out in favour of much faster methods. The Open Hearth process at Bilston was prefixed as ‘Basic’ which referred to the lining of the furnace which could be either ‘Basic’ or ‘Acid’ depending on the type of iron being processed. Typically Acid linings were only used in the northwest. Open Heath steelmaking which took place generally in many older small or medium size plants dotted about Britain was phased out in the 1970’s resulting in the closure of those works and replacement by a small number of very large, modern steelworks, typically on coastal locations for ease of handling the huge volumes of imported iron ore. Steelmaking at these new plants employed a much faster and new process called Basic Oxygen Conversion which could convert 300 tonnes of iron to steel in twenty minutes compared to eight to ten hours. Other steelworks were built, mainly in the Sheffield/Rotherham area, using the Electric Arc process which was more suited to scrap feed and the production of engineering steels. It was the use of the older Open Hearth process at Bilston which unfortunately added to the argument in favour of closing the works.


Diagram of a Blast Furnace

Diagram of a Blast Furnace


This clearly shows the working of a blast furnace and the principles of how the raw materials go in at the top and iron comes out at the bottom. You can see here the configuration of Elisabeth. Note the raw materials are : coke, sinter, iron ore and limestone. Sinter (an agglomeration of fines and fragments) was not charged to Elisabeth since there was no sinter line facility at Bilston – however a product called millscale was. Millscale is a flake of metal which falls off during hot processing. This is of course iron rich and therefore good to be recycled back into the blast furnace. The only problem with it was that being brittle it disintegrated into ‘fines’ and could clog the furnace if charged in large quantities.


Diagram of an Open Hearth Furnace

Diagram of an Open Hearth Furnace


Bilston’s furnaces were just as this except there was no roof mounted oxygen lance installation.