Steelmaking

Steelmaking is the process of converting iron ore and/or scrap into steel for use in various applications. The process of steelmaking involves the removal of impurities from iron sourced from the environment such as nitrogen, silicon, phosphorus, sulphur, and excess carbon (the most significant impurity). Alloying elements such as manganese, nickel, chromium, carbon, and vanadium are then added to produce different grades of steel. Preventing dissolved gases such as nitrogen and oxygen from forming in the steel and entrained impurities (also known as "inclusions") from forming is also vital for ensuring the quality of items cast from liquid steel.

Despite the fact that steelmaking has been around for millennia, it was not marketed on a large scale until the late fourteenth century. The crucible method was a steelmaking technique that dates back thousands of years. The Bessemer process and the Siemens-Martin process, which were developed in the 1850s and 1860s, transformed steelmaking into a major industry. Basic oxygen steelmaking, in which liquid pig-iron from the blast furnace and scrap steel serve as the primary feed materials, and electric arc furnace (EAF) steelmaking, in which scrap steel or direct reduced iron (DRI) serve as the primary feed materials, are the two most widely used commercial steelmaking processes today. In contrast to EAF steelmaking, which uses electrical energy to melt solid scrap and/or DRI materials, oxygen steelmaking is primarily powered by the exothermic nature of the reactions occurring within the vessel; in oxygen steelmaking, the reactions occur outside the vessel. Due to the introduction of additional chemical energy into the process in recent years, EAF steelmaking technology has progressed closer to oxygen steelmaking technology.

Steelmaking is one of the most carbon-intensive businesses on the planet, emitting more carbon dioxide than any other. The steel industry is expected to be responsible for 7 to 9 percent of all direct fossil-fuel greenhouse gas emissions by 2020, according to estimates. In order to combat global warming, the industrial sector will need to discover ways to reduce emissions of greenhouse gases. When it comes to decarbonization, McKinsey highlighted a variety of technologies that might be implemented by 2020. These included the use of hydrogen, carbon capture and reuse, and increasing the use of electric arc furnaces that were driven by renewable energy.