US3193382A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the recovery of zinc from zinc plant residues
Assignee: Viridian Inc Canada
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Filing: 1963-01-09
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Granted: 1965-07-06
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Expires: 1983-01-09
Abstract
No abstract record available.
Inventors
- 👤 Herbert O K Veltman
- 👤 Whayman Edward
- 👤 Haigh Curzon John
- 👤 Pickering Ralph Watt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:18
CPC Classifications
C; C22; C22B; C22B19/00; C22B19/20; C22B19/22; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
140 words
IN A PROCESS FOR THE EXTRACTION OF ZINC FROM ZINC PLANT RESIDUE CONTAINING ZINC FERRITE IN WHICH THE RESIDUE IS SUBJECTED TO A FIRST STAGE PRESSURE LEACHING TREATMENT IN A SUBSTANTIALLY OXYGEN FREE ATMOSPHERE IN A CLOSED VESSEL AT A TEMPERATURE BETWEEN 150*C. AND 220*C. IN THE PRESENCE OF SULPHURIC ACID IN EXCESS OF THAT STOICHIOMETRICALLY EQUIVALENT TO THE ZINC IN THE RESIDUE, AND THEN SAID RESIDUE IS SUBJECTED TO A SECOND STAGE PRESSURE LEACHING TREATMENT UNDER OXIDIZING CONDITIONS IN A CLOSED VESSEL IN THE PRESENCE OF SULPHURIC ACID AT A TEMPERATURE BETWEEN 150*C. AND 200*C., THE IMPROVEMENT WHICH COMPRISES CONDUCTING THE FIRST STAGE LEACHING TREATMENT IN THE PRESENCE OF A REDUCING AGENT SELECTED FROM THE GROUP CONSISTING OF ZINC SULPHIDE, METALLIC ZINC POWDER, SULPHUR DIOXIDE AND HYDRAZINE SULPHATE IN AMOUNT SUFFICIENT TO PRODUCE REDUCING CONDITIONS IN SAID FIRST STAGE.
Claim 2
Dependent Claim
140 words
IN A PROCESS FOR THE EXTRACTION OF ZINC FROM ZINC PLANT RESIDUE CONTAINING ZINC FERRITE IN WHICH THE RESIDUE IS SUBJECTED TO A FIRST STAGE PRESSURE LEACHING TREATMENT IN A SUBSTANTIALLY OXYGEN FREE ATMOSPHERE IN A CLOSED VESSEL AT A TEMPERATURE BETWEEN 150*C. AND 220*C. IN THE PRESENCE OF SULPHURIC ACID IN EXCESS OF THAT STOICHIOMETRICALLY EQUIVALENT TO THE ZINC IN THE RESIDUE, AND THEN SAID RESIDUE IS SUBJECTED TO A SECOND STAGE PRESSURE LEACHING TREATMENT UNDER OXIDIZING CONDITIONS IN A CLOSED VESSEL IN THE PRESENCE OF SULPHURIC ACID AT A TEMPERATURE BETWEEN 150*C. AND 200*C., THE IMPROVEMENT WHICH COMPRISES CONDUCTING THE FIRST STAGE LEACHING TREATMENT IN THE PRESENCE OF A REDUCING AGENT SELECTED FROM THE GROUP CONSISTING OF ZINC SULPHIDE, METALLIC ZINC POWDER, SULPHUR DIOXIDE AND HYDRAZINE SULPHATE IN AMOUNT SUFFICIENT TO PRODUCE REDUCING CONDITIONS IN SAID FIRST STAGE.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-07-05 | 1969-01-04 | 1969-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-07-05 | 1973-01-04 | 1973-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-07-05 | 1977-01-04 | 1977-07-06 | $7700.00 | Window Closed / Lapsed |