Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4810371 | Process for fine coal cleaning | — | 1989-03-07 |
| 4324560 | Pyrite removal from coal | — | 1982-04-13 |
| 4253703 | Method for mining coal using ammonia and nitrifying bacteria | Bruce Bray, Randolph Kosky | 1981-03-03 |