Process for extraction of alumina from alumina-containing ore
Abstract
Abstract AMMONIUM SULPHATE IS ADDED TO ALUMINA-BEARING ORE, SUCH AS CLAY, IN STOICHIOMETRIC PROPORTION TO THE AMOUNT OF ALUMINA PRESENT IN THE ORE, THE MIXTURE IS PELLETIZED, AND THE PELLETS, PREFERABLY ABOUT ONE INCH IN DIAMETER ARE HEATED IN A SPECIALLY CONSTRUCTED PLUGGED FLOW FURNACE TO A TEMPERATURE ABOVE THE DECOMPOSITION TEMPERATURE OF IRON SULPHATE AND BELOW THE DECOMPOSITION TEMPERATURE OF ALUMINUM SULPHATE. UPON COOLING, THE PELLETS ARE PLACED IN WATER TO FORM AN ALUMINUM SULPHATE SOLUTION WHICH IS FILTERED AND THEN REACTED WITH AMMONIA GAS TO FORM A PRECIPITATE OF ALUMINUM HYDROXIDE WHICH CAN BE FILTERED, WASHED AND DRIED. THE FURNACE OR KILN INCLUDES UPPER AN LOWER CHAMBERS OF THE SAME DIAMETER AND A REDUCED DIAMETER INTERMEDIATE CHAMBER. HOT GASES ARE INTRODUCED BY TUYERS COMMUNICATING WITH AN ANNULAR SPACE DEFINED AT THE JUNCTURE BETWEEN THE INTERMEDIATE AND LOWER CHAMBERS. A ROTATING TABLE IN COMBINATION WITH ADJUSTABLE DRAG BARS BOTH LOCATED BELOW THE LOWER CHAMBER CONTROL THE RATE OF FLOW OF MATERIAL THROUGH THE FURNACE.
Inventors
- 👤 George Miller
Bibliographic Details
Claims Analysis
Total Claims: 0References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-19 | 1975-01-18 | 1975-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-19 | 1979-01-18 | 1979-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-19 | 1983-01-18 | 1983-07-20 | $7700.00 | Window Closed / Lapsed |