| Naics index | Naics index description |
|---|---|
| 331410 | Nickel refining, primary |
| 331410 | Niobium refining, primary |
| 331410 | Copper smelting and refining, primary |
| 331410 | Antimony refining, primary |
| 331410 | Bars made in primary copper smelting and refining mills |
| 331410 | Beryllium refining, primary |
| 331410 | Bismuth refining, primary |
| 331410 | Blister copper manufacturing |
| 331410 | Cadmium refining, primary |
| 331410 | Chromium refining, primary |