Manufacture of composite ferrites
Abstract
Abstract Ferrite powder of consistent good quality and homogeneity is obtained by using nitric acid to form solutions of the nitrate of each of the metals involved, mixing the solutions in the requisite proportions, and decomposing the mixture by spray deposition on the hot surface of an agitated bed of granular material identical with the decomposition product while avoiding any accumulation of liquid, and then calcining the obtained oxide mixture to obtain ferrite powder with a desired proportion of ready-formed ferrite. The nitrous gases formed during solution and decomposition are used for the reconstitution of nitric acid, the tail gas of the reconstitution system being preferably contacted with an aqueous suspension of a basic oxide of a constituent metal of the ferrite, whereafter nitric acid is added to form the required nitrate solution of the constituent metal.
Inventors
- 👤 Frederick Claud Cowlard
- 👤 George Ord
Bibliographic Details
Claims Analysis
Total Claims: 2References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |