Steelmaking is the branch of metallurgy dedicated to the manufacture and treatment of steel and cast iron. Steel production begins with the production of raw material, which can be iron ore or steel scrap. Iron ore is extracted from commercial reserves through mining. Industrial processes such as beneficiation separate iron ore from the commercially worthless material called gangue. These processes include crushing, grinding, screening, magnetic separation, among others. The production cost varies depending on the content of the rock extracted and the need for more or less processing.