Recovery of metal values
Abstract
Abstract PREPARATION OF ZINC ELECTROLYTE FROM ZINCIFEROUS ORE IN WHICH THE FERRITIC RESIDUE FROM THE USUAL LEACH IS RELEACHED IN THE PRESENCE OF A REDUCING AGENT SUCH AS METALLIC IRON, TO PRODUCE A FILTRATE HAVING AN IRON CONTENT OF 20-60 GRAMS PER LITER, AND WHEREIN THE LAST-MENTIONED FILTRATE IS, IN SUCCESSIVE STAGES, NEUTRALIZED AND OXIDIZED CONCOMITANTLY WITH PRECIPITATION OF THE IRON THEREFROM, FIRST WHILE THE PH VALUE IS MAINTAINED BELOW 4.0 AND PREFERABLY IN THE RANGE OF 1.5 TO 3.6 UNTIL THE MAJOR PORTION OF THE IRON HAS BEEN PRECIPITATED IN A FORM READILY SEPARABLE FROM THE LIQUID PHASE, AND SECOND WHILE THE PH VALUE OF SAID IRON-DEPLETED SOLUTION IS MAINTAINED AT A PH VALUE OF 4 TO 4.5. D R A W I N G
Inventors
- 👤 Robert K Carpenter
- 👤 Richard F Pagel
Bibliographic Details
Claims Analysis
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-29 | 1976-02-28 | 1976-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-29 | 1980-02-28 | 1980-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-29 | 1984-02-28 | 1984-08-29 | $7700.00 | Window Closed / Lapsed |