Ferrotitanium is a ferroalloy, an alloy of iron and titanium with between 10–20% iron and 45–75% titanium and sometimes a small amount of carbon. It is used in steelmaking as a cleansing agent for iron and steel; the titanium is highly reactive with sulphur, carbon, oxygen, and nitrogen, forming insoluble compounds and sequestering them in slag, and is therefore used for deoxidizing, and sometimes for desulfurization and denitrogenation. In steelmaking the addition of titanium yields metal with finer grain structure. Ferrotitanium powder can be also used as a fuel in some pyrotechnic compositions.