Minor metals cover a metals range of significant economical importance, but which traded volume is much lower than ferrous or base metals.
A good overview of how different metals are extracted, refined and used is given by Umicore .
Cobalt is fairly common (25 ppm of the earth's crust), found in various minerals. Most cobalt recovered from ores arises as a by-product of copper and nickel metallurgy. Recycling is important as well.
Cobalt is a bluish-grey, hard, lustrous metal. Main usages are: superalloys, pigments, chemicals, catalysts, batteries and dyes.
More on cobalt: Cobalt institute .
Molybdenum is not very abundant (1.5 ppm of the earth's crust). Main mineral is molybdenite. Molybdenum ore excavation is often linked to copper mines.
Molybdenum is a silvery-white, strong metal. It has one of the highest melting temperature and lowest thermal expansion and is very resistant to corrosion. Main usages are: alloys addition to various metals (strength, temperature resistance, anti-corrosion), chemicals.