In-situ generation of acid for in-situ leaching of copper
Abstract
Abstract In-situ leaching of underground, copper-bearing ore deposits or waste dumps containing copper sulfide minerals is accomplished by introducing a hydraulic fluid containing particulate pyrite into the underground ore deposit or waste dumps under sufficient pressure to fracture the formation and to deposit the pyrite particles contained in the fluid in the fractures as a propping agent. An aqueous leach liquid and oxygen is then injected into the formation. The oxygen injected into the formation reacts with the pyrite propping agent in the presence of the aqueous leach liquid to rapidly produce ferric sulfate and sulfuric acid, which rapidly dissolves the copper sulfide minerals. The dissolution of the copper sulfide is accelerated by the in-situ generation of heat due to the oxygen reacting with the particulate pyrite, as well as by galvanic action set up at points of contact between the particulate pyrite and the metal sulfides in the underground ore deposit or waste dump.
Inventors
- 👤 H Spedden
- 👤 E Maloue
Bibliographic Details
Claims Analysis
Total Claims: 5References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |