Molybdenum is mainly used in metallurgical applications, with the majority of molybdenum produced used in alloys, such as structural and stainless steel, cast iron and superalloys. It is also used to produce chemicals, such as plant fertilizer, pigments, adhesives and lubricants, and in medical applications, such as some x-ray and imaging equipment. Molybdenum is a necessary trace element for animals and most plants.
Molybdenum's melting point is very high and it is used in alloys to increase strength, hardness, electrical conductivity and resistance to wear and corrosion. It is used as an anode to replace tungsten in low-level x-ray equipment, in heating elements and in machining tools and saw blades. It is used in power plants as a catalyst in the control of nitrogen, oxygen and sulfur compounds.
In plants and animals, molybdenum plays an important role in the production of organic nitrogen compounds. Some evidence suggests that a scarcity of molybdenum in the Earth's early oceans delayed the evolution of higher plant and animal life for about two billion years, until early life produced enough oxygen in the oceans to form compounds with molybdenum present on the sea floor, making sufficient molybdenum available for higher life forms to evolve.