http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-825100-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_c05c217a2f91f2bbda93b8a4c02aaa2d |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C22B60-0213 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C22B60-02 |
| filingDate | 1957-04-09-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1959-12-09-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-825100-A |
| titleOfInvention | Recovery of uranium from low grade uranium bearing ores |
| abstract | <PICT:0825100/III/1> Uranium values are recovered from a mixture containing free or combined aluminium, iron and uranium by chlorinating the mixture and passing the vapours in contact with molten alkali metal chloride to selectively deposit uranium chloride therein, and thereafter separating the uranium values from the alkali metal chloride. The invention is particularly applicable to the recovery of uranium from low grade shales which are preferably heated to 450 DEG to 800 DEG C., to remove volatile organic components before reaction with a chlorinating agent at 600 DEG to 1000 DEG C. Suitable chlorinating agents are phosgene, carbon tetrachloride, chlorine and a mixture of chlorine and sulphur chloride; volatile matter is preferably removed from the shale prior to chlorination by retorting or roasting for example in a fluidized solid roaster. As shown in Fig. 1, shale is crushed and fed to a retort with steam or recycled combustion gases and heated at 450 DEG to 800 DEG C.; the combustion gases can be recycled. The heated shale is then chlorinated preferably with chlorine diluted with dry nitrogen and the metal chloride stream is freed from entrained solids in a separator operating at 700 DEG to 900 DEG C. The chloride stream is then passed to a molten alkali metal chloride maintained at 700 DEG to 1000 DEG C. whereby the uranium chloride is selectively extracted. Uranium values are recovered by cooling the alkali metal chloride bed, dissolving in water and acidifying the solution with nitric or sulphuric acid after which the uranium values may be extracted with a selective organic solvent such as benzylamine or diethyl ether. Metal chlorides not extracted by the alkali metal chloride may be condensed at 100 DEG to 300 DEG C. to remove aluminium, ferric, and potassium chlorides, whilst leaving silicon and titanium chloride with sulphur chlorides and chlorine in the vapour stream. Chlorine and sulphur chlorides are separated and recycled to the chlorination zone. The condensed aluminium, ferric, and potassium chloride mixture is vaporized and the resulting chloride stream may be passed through ferric oxide to convert the aluminium chloride to a commercial grade alumina. The resulting ferric chloride may be reacted with oxygen at 1000 DEG C. for form ferric oxide and chlorine, the latter being recycled. Alternatively the chloride stream leaving the molten alkali metal chloride which has absorbed the uranium may be contacted with further alkali metal chlorides, such as potassium, at 500 DEG to 650 DEG C., whereby iron and aluminium chlorides are retained in the alkali metal chloride. The resulting mass may be heated in an oxidizing atmosphere to form chlorine and a mixture of ferric and aluminium oxides which may be separated by known means. |
| priorityDate | 1956-06-06-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
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