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Molybdenumis mainly obtained from the ores molybdenite (molybdenum sulphide) and wulfenite (lead molybdate) which are concentrated by flotation, converted into the oxide and then reduced to the metal.
The metal is obtained either in a compact form suitable for rolling, drawing, etc., or as a powder which can be sintered like tungsten (see the Explanatory Note to heading 81.01).
Molybdenum in the compact form resembles lead in appearance, but it is extremely hard and melts at a high temperature. It is malleable and, at normal temperatures, resists corrosion.
Molybdenum is used (either as the metal or as ferro-molybdenum, of Chapter 72) for the manufacture of alloy steels. Molybdenum metal is also used in filament supports for electric light bulbs; grids of electronic valves; elements for electric furnaces; current rectifiers and electric contacts. It is also used in dentistry, and as a substitute for platinum in jewellery because it does not tarnish.
The molybdenum alloys in general use do not contain a predominance of molybdenum and are therefore excluded from this heading in accordance with Note 5 to Section XV.
Since the metallurgy of molybdenum resembles that of tungsten, the second part of the Explanatory Note to heading 81.01 (concerning the forms in which the metal is marketed, and the classification of the carbide) applies, mutatis mutandis, to this heading.
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