US4180546A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for removing phosphorus from phosphorus-containing fluorite
Assignee: Central Glass Co Ltd
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Filing: 1978-07-19
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Granted: 1979-12-25
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Expires: 1998-07-19
Abstract
Abstract A process for removing a phosphorus component from fluorite containing such phosphorus component, which process comprises adding powder of the fluorite to an aqueous acid solution having an acid concentration of from 1.0 to 20 Wt% in an inorganic acid/phosphorus ratio of above 25:1 by mole to give a slurry, agitating the slurry at a temperature below 50° C., and collecting the powder from the slurry. The mother liquor obtained after separation of the powder from the slurry may be recycled to the first step.
Inventors
- 👤 Toshiyuki Shibata
- 👤 Hiroshi Ono
- 👤 Kenji Isoyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:35
CPC Classifications
C; C01; C01F; C01F11/00; C01F11/20; C01F11/22; C01F11/02; C01F11/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
68 words
A process for removing a phosphorus impurity from fluorite, the process comprising adding powder of fluorite containing the phosphorus impurity to an aqueous solution of an inorganic acid having an acid concentration of from 1.0 to 20 Wt% in an inorganic acid/phosphorus ratio of above 25:1 by mole to give a slurry, agitating the slurry at a temperature below 50° C., and collecting the powder from the slurry.
Claim 2
Dependent Claim
68 words
A process for removing a phosphorus impurity from fluorite, the process comprising adding powder of fluorite containing the phosphorus impurity to an aqueous solution of an inorganic acid having an acid concentration of from 1.0 to 20 Wt% in an inorganic acid/phosphorus ratio of above 25:1 by mole to give a slurry, agitating the slurry at a temperature below 50° C., and collecting the powder from the slurry.
Claim 3
Dependent Claim
19 words
A process according to claim 1, wherein the inorganic acid/phosphorus ratio by mole is in the range of 30-300:1.
Claim 4
Dependent Claim
20 words
A process according to claim 1, wherein the powder content in the slurry is in the range of below 50%.
Claim 5
Dependent Claim
34 words
A process according to claim 1, wherein the powder is collected by filtration and then washed with water, and the resulting filtrate is recycled to the first step for use as the aqueous solution.
Claim 6
Dependent Claim
16 words
A process according to claim 1, wherein the powder has a particle size of below 100μ.
Claim 7
Dependent Claim
16 words
A process according to claim 1, wherein the agitation is continued for at least 10 minutes.
Claim 8
Dependent Claim
20 words
A process according to claim 1, wherein the acid concentration is in the range of from 2.5 to 20 Wt%.
References Cited (Backward Citations)
US3065050A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-12-24 | 1983-06-25 | 1983-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-24 | 1987-06-25 | 1987-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-24 | 1991-06-25 | 1991-12-25 | $7700.00 | Window Closed / Lapsed |