Issued Patents All Time
Showing 1–25 of 29 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6135372 | Hydroxy-carboxylic acid grinding aids | — | 2000-10-24 |
| 5799882 | Hydroxy-carboxylic acid grinding aids | — | 1998-09-01 |
| 5244155 | Solid-solid separations utilizing alkanol amines | Basil S. Fee, Donald E. Leonard | 1993-09-14 |
| 5173176 | Dialkylated aryl monosulfonate collectors useful in the flotation of minerals | Donald E. Leonard, Kevin A. Frazier | 1992-12-22 |
| 5171427 | Sulfonated and carboxylate collector compositions useful in the flotation of minerals | Donald E. Leonard, Gordon D. McCann | 1992-12-15 |
| 5169518 | Recovery of petroleum from tar sands | Basil S. Fee | 1992-12-08 |
| 5131600 | Alkanol amine grinding aids | Donald E. Leonard, Basil S. Fee | 1992-07-21 |
| 5124028 | Froth flotation of silica or siliceous gangue | — | 1992-06-23 |
| 5057209 | Depression of the flotation of silica or siliceous gangue in mineral flotation | Donald E. Leonard, Robert D. Hansen, Basil S. Fee | 1991-10-15 |
| 5015367 | Alkylated diaryl oxide monosulfonate collectors useful in the floatation of minerals | Donald E. Leonard | 1991-05-14 |
| 4830740 | Pyrite depressants useful in the separation of pyrite from coal | Robert D. Hansen | 1989-05-16 |
| 4826588 | Pyrite depressants useful in the separation of pyrite from coal | Robert D. Hansen, Michael J. Fazio | 1989-05-02 |
| 4822483 | Collector compositions for the froth flotation of mineral values | Robert D. Hansen | 1989-04-18 |
| 4820406 | Method for the froth flotation of coal | Robert D. Hansen | 1989-04-11 |
| 4808301 | Flotation depressants | Robert D. Hansen | 1989-02-28 |
| 4797202 | Froth flotation method | Robert D. Hansen | 1989-01-10 |
| 4789392 | Froth flotation method | Robert D. Hansen | 1988-12-06 |
| RE32778 | Frothers demonstrating enhanced recovery of coarse particles in froth floatation | Robert D. Hansen, Roger W. Bergman | 1988-11-08 |
| 4770767 | Method for the froth flotation of coal | Robert D. Hansen | 1988-09-13 |
| 4761223 | Frothers demonstrating enhanced recovery of fine particles of coal in froth flotation | Robert D. Hansen | 1988-08-02 |
| 4735711 | Novel collectors for the selective froth flotation of mineral sulfides | Robert D. Hansen, Edwin J. Strojny | 1988-04-05 |
| 4732668 | Novel collectors for the selective froth flotation of mineral sulfides | Robert D. Hansen, Edwin J. Strojny | 1988-03-22 |
| 4702822 | Novel collector composition for froth flotation | Robert D. Hansen | 1987-10-27 |
| 4684459 | Collector compositions for the froth flotation of mineral values | Robert D. Hansen | 1987-08-04 |
| 4676890 | Collector compositions for the froth flotation of mineral values | Robert D. Hansen | 1987-06-30 |