Recycling of catalysts

Recycling process

The process developed by Valdi makes it possible to treat the used hydrotreating catalysts (HDS) “CoMo”, “NiMo”, “NiCoMo”, NiW “resulting  the treatments in the oil industry.

A first roasting process will desulfurize spent catalysts. Sulfur will be reprocessed to make sodium sulphate for different industrial sectors.

Roasted catalysts will then be melted in a submerged electrode furnace and refined in a converter to produce alloys based on nickel and molybdenum or cobalt and molybdenum.

The surface portion (slag) will concentrate the base of the high alumina catalyst to serve as raw material in the glass wool industry or in facade coatings.

Products and recycling

  • Alloys  FeNiMo :      up to 28%Mo, 12% Ni
  • Alloys FeCoMo:       up to 28% Mo, 6% Co
  • Aluminate dairy :     up to 38% of alumina

There is no waste generated in a spent catalyst recycled by VALDI:

  • Sulfur is recycled as sodium sulphate,
  • The support of catalysts (mainly alumina ball) will be found in aluminate slags
  • All non-ferrous metals will be recycled as alloys​