- Antifriction bearing metals, lead-base (1)
- Lead smelting and refining (primary) (1)
- Zinc refining (primary), including slabs & dust (1)
- Zinc smelting (primary), including zinc residue (1)
- Precious metals (10)
- Platinum group metal refining (primary) (1)
- Silicon refining (primary, over 99% pure) (3)
- Silicon, pure (2)
