Environment protecting hydrometallurgical processes associated with the manufacture of some tungsten based products. II. Dissolution of the molybdenum mandrel wire from tungsten coils

The basic hydrometallurgical operation of the tungsten filament manufacturing, the molybdenum mandrel wire dissolving has been reviewed from environmental and hygienic aspects presenting the published efforts for streamlining of the traditional H₂SO₄---HNO₃ mixture based process.

The fundamentals of a new environment-preserving and hygienic process based on H₂O₂-catalyst mixture are outlined as well as its development and industrial implementation to a zero effluent discharging process and equipment consisting of selective molybdenum dissolving from tungsten coils and the recovery of the dissolved molybdenum and process water.

Some desirable development potentials of the new process are sketched considering scientific, technical, economical and environmental aspects.