1. Tungsten trading forms

The various commercial forms of tungsten are :

• ores and concentrates (scheelite, wolframite) ;

• tungstates: sodium tungstate, ammonium metatungstate (AMT) and especially ammonium paratungstate (APT);

• oxides: trioxide WO ₃ , blue oxide (TBO) and tungstic acid H ₂ WO ₃ ;

• tungsten metal powders ;

• WC tungsten carbide powders ;

• fused carbide powders (eutectic WC-W ₂ C) ;

• ferrotungsten ;

• tungstic waste ;

• ...