The manufacturing of steel involves many stages. The basic raw materials were coal, iron ore, limestone and various chemicals in the open hearth. Now it is recycled scrap including cars, buildings, appliances, as well as alloy scrap for different products. The process moves from combining raw materials in the furnace to forming molten casts which are then transformed into steel slabs. Once the steel is made into slabs, it is processed for customers.
The process is fascinating to view because of the extremes of the operation, including the massive scale of production and the extreme temperatures involved. As demand for larger steel grew so did the scale of the size of the process including steel making and rolling mills.