Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 8323377 | Recovery of metals from oxidised metalliferous materials | Frank Houllis, Andrew Tong | 2012-12-04 |
| 7858056 | Recovering metals from sulfidic materials | Frank Houllis | 2010-12-28 |
| 7465334 | Zinc recovery process | Frank Houllis | 2008-12-16 |