Ferromolybdenum is an important iron molybdenum alloy, with a molybdenum content of 60-70% It is the main source for molybdenum alloying of HSLA steel. The molybdenum is mined and is subsequently transformed into the molybdenum(VI) oxide MoO3. This oxide is mixed with iron oxide and aluminium and is reduced in the an aluminothermic reaction to molybdenum and iron. The ferromolybdenum can be purified by electron beam melting or used as it is.
Molybdenum disulfide is the inorganic compound with the formula MoS2. This black crystalline sulfide of molybdenum occurs as the mineral molybdenite. It is the principal ore from which molybdenum metal is extracted. The natural amorphous form is known as the rarer mineral jordisite. MoS2 is less reactive than other transition metal chalcogenides, being unaffected by dilute acids.
Molybdenum trioxide is chemical compound with the formula MoO3. This compound is produced on the largest scale of any molybdenum compound. It occurs as the rare mineral molybdite. Its chief application is as an oxidation catalyst and as a raw material for the production of molybdenum metal.