It depends on the type of steel mill. If the mill has a blast furnace you would consume coke, iron ore, and limestone. It would produce molten steel and slag. The slag would go to a slag dump to cool. The molten steel would then be moved to the Basic Oxygen Furnace where the it would be made into slabs, from there the steel slabs would be moved to a rolling mill for cutting and other refinements. It is also possible the plant could have an electric arc furnace where scrap metal is brought in and melted down and made into new steel slabs and then moved to the rolling mill, again for cutting and refinement. The rolling mill will ship out plates, coils and other types of steel. A lot of plants have a pipe mill where the steel is rolled into pipe so that is also another possible outbound load.
Disclaimer: this is all from memory so all information may not be 100% accurate.