- Lead smelting and refining (secondary) (1)
- Secondary precious metals (7)
- Gold smelting and refining (secondary) (5)
- Silver recovery from used photographic film (1)
- Aluminum smelting and refining (secondary) (8)
- Babbitt metal smelting and refining (secondary) (1)
- Brass smelting and refining (secondary) (1)
- Copper smelting and refining (secondary) (1)
- Magnesium smelting and refining (secondary) (1)
- Nickel smelting and refining (secondary) (1)
- Recovery and refining of nonferrous metals (3)
