Chromium is mainly used in the form of ferroalloys (such as ferrochrome) in the production of stainless steel and various alloy steels. Chromium metal is used as an additive in aluminum alloys, cobalt alloys, titanium alloys, high-temperature alloys, resistance heating alloys, etc. Chromium oxide is used as a light resistant and heat-resistant coating, as well as an abrasive, a coloring agent for glass and ceramics, and a catalyst for chemical synthesis. Basic chromium sulfate (trivalent chromium salt) is used as a tanning agent for leather. Chromium alum and dichromate are used as mordant, impregnating agent, and various pigments for fabric dyeing. Chromium plating and infiltration can form a corrosion-resistant surface for steel, copper, aluminum and other metals, and are bright and beautiful. They are widely used in industries such as furniture, automobiles, and construction.