| 75 / | HD | SPECIALIZED METALLURGICAL PROCESSES, COMPOSITIONS FOR USE THEREIN, CONSOLIDATED METAL POWDER COMPOSITIONS, AND LOOSE METAL PARTICULATE MIXTURES |
| 330 | DF | PROCESSES {9} |
| 392 | DF | .~ Producing or treating free metal {10} |
| 710 | DF | .~.~ Below 300 degrees C {2} |
| 711 | DF | .~.~.~ Using nonmetallic material which is liquid under standard conditions (e.g., hydrometallurgy, etc.) {11} |
| 717 | DF | .~.~.~.~ Reducing to free metal with gas {2} |
| 718 | | .~.~.~.~.~ Copper (Cu) recovered as free metal {1} |
| 719 | DF | .~.~.~.~.~.~> Using Sulfur dioxide |