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US3963824A
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Process for extracting chromium from chromium ores
Assignee: Produits Chimiques Ugine Kuhlmann
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Filing: 1975-06-10
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Granted: 1976-06-15
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Expires: 1995-06-10
Abstract
Abstract Process of extracting chromium from a chromium ore or concentrate by oxidation, which comprises suspending the chromium ore or concentrate in a bath of molten salts and introducing an oxygen-containing gas into the suspension in a sufficient amount and for a sufficient amount of time to oxidize chromium therein.
Inventors
- 👤 Roland Bachelard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:03
CPC Classifications
C; C01; C01G; C01G37/00; C01G37/14; C22; C22B; C22B34/00; C22B34/30; C22B34/32
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
103 words
A process for extracting chromium in the form of a chromate from ore or concentrate by the suspension oxidation thereof to the chromate state which comprises suspending finely crushed ore or concentrate containing the chromium in a molten liquid bed of an alkali metal salt in the ratio of 1 part by weight of ore to 5 to 20 parts by weight of salt; subjecting the suspension to agitation with an oxygen-containing gas at a temperature and for a time sufficient to convert the chromium to alkali metal chromates; and leaching with water to separate out the water soluble chromates from insoluble residue.
Claim 2
Dependent Claim
103 words
A process for extracting chromium in the form of a chromate from ore or concentrate by the suspension oxidation thereof to the chromate state which comprises suspending finely crushed ore or concentrate containing the chromium in a molten liquid bed of an alkali metal salt in the ratio of 1 part by weight of ore to 5 to 20 parts by weight of salt; subjecting the suspension to agitation with an oxygen-containing gas at a temperature and for a time sufficient to convert the chromium to alkali metal chromates; and leaching with water to separate out the water soluble chromates from insoluble residue.
Claim 3
Dependent Claim
24 words
The process of claim 1 wherein the chromium is in the form of an ore having a mean size of less than 250 microns.
Claim 4
Dependent Claim
36 words
The process of claim 1 in which the alkali metal salt forming the molten liquid bed is selected from sodium carbonate, sodium chromate, potassium carbonate, potassium chromate, sodium sulfate, potassium sulfate, potassium bichromate, or mixtures thereof.
Claim 5
Dependent Claim
19 words
The process of claim 3 in which the alkali metal salt forming the molten liquid bed is sodium carbonate.
Claim 6
Dependent Claim
20 words
The process of claim 3 in which the oxygen-carrying gas is introduced at the surface of the molten liquid bed.
Claim 7
Dependent Claim
34 words
The process of claim 3 wherein the mixtures of alkali metal salts forming the molten liquid bed is selected from eutectic mixtures of sodium chromate and sodium carbonate, or potassium chromate and potassium bichromate.
Claim 8
Dependent Claim
16 words
The process of claim 1 wherein the molten liquid bed contains sodium sulfate as a diluent.
Claim 9
Dependent Claim
26 words
The process of claim 1 wherein the molten liquid bed contains a sufficient quantity of an oxidation catalyst to increase the rate of the oxidation reaction.
Claim 10
Dependent Claim
18 words
The process of claim 8 wherein the oxidation catalyst is iron oxide, manganese oxide, or a mixture thereof.
References Cited (Backward Citations)
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US3510256A
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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) | 1979-06-15 | 1979-12-15 | 1980-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-15 | 1983-12-15 | 1984-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-15 | 1987-12-15 | 1988-06-15 | $7700.00 | Window Closed / Lapsed |