The furnace is refractory-lined with a castable refractory material and looks almost like a very large kitchen “stew pot.” The basic ingredient for the electric-arc furnace melt is very carefully analyzed scrap steel.
Once the scrap has been deposited into the furnace, the roof of the furnace is closed and the electrodes inserted through the roof to strike an arc with the scrap steel (very similar to the process of electric welding). The scrap is then very carefully melted, a sample is analyzed and the appropriate additive alloying elements are added.
The process is extremely noisy and one does require ear protection if in close proximity to the furnace when it is operating. The electric arc furnace consumes tremendous amounts of electrical power as well as consuming the electric-arc carbon electrodes.
Once the scrap steel has been melted, the other additive elements are added such as limestone for fluxing. If the carbon content of the steel is too high, the plain iron (unalloyed, no carbon) is added to increase the iron content and reduce the carbon content simply by dilution.
The process of making the melt to a “ready-to-pour” temperature and analysis will generally take around six hours. Then the slag is removed from the top of the melt, simply by pouring it off. The “clean steel” is then poured into ingots.
The steel is now ready for hot rolling into shapes and forms such as plate, hot-rolled bar, channels and sections.