http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-780477-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_8fc0668fd5cbfe23cea7d9bdd5de932a |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C22B34-14 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C01G25-04 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C22B34-14 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C01G25-04 |
| filingDate | 1953-06-03-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| inventor | http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_fd0ba7863083dfa3a0c4149f0476616a |
| publicationDate | 1957-08-07-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-780477-A |
| titleOfInvention | A process for removal of hafnium from zirconium-containing material |
| abstract | Hafnium is removed from zirconium or its compounds by converting the zirconium or compounds thereof and the associated hafnium into tetrahalides, reducing the tetrahalide of zirconium to a lower halide or to metallic zirconium whilst leaving the hafnium tetrahalide unreduced, and separating the hafnium tetrahalide and any unreduced zirconium tetrahalide from the zirconium reduction products. The reduction may be effected with metallic zirconium, magnesium, aluminium, or zinc but preferably with zirconium dihalide which may be produced by the treatment of an initial batch of zirconium and hafnium tetrahalides with finely divided metallic zirconium. According to the preferred procedure, tetrahalides of zirconium and hafnium are formed and sublimed on to cooled coils of a removable lid of a reaction chamber, which lid is then transferred to another reaction chamber where the tetrahalides are volatilized and brought into contact with zirconium dihalide whereby the zirconium tetrahalide is reduced to relatively non-volatile lower halides, the hafnium tetrahalide being removed by vacuum pumps from the reaction vessel. The temperature of the vessel is then increased whereby the zirconium lower halides probably the trihalides disproportionate into pure zirconium tetrahalide which condenses on the cooled reaction chamber lid, and zirconium dihalide which remains in the vessel and may be employed in the treatment of the next batch. The reduction may be effected in vacuo or in an atmosphere of an inert gas such as argon. The hafnium-free zirconium tetrahalide which is recovered on the cooled reactor lid may be reduced with magnesium followed by vacuum distillation of the magnesium chloride and excess magnesium to obtain a zirconium sponge which may be melted in a resistance furnace to form zirconium ingots. Alternatively after the reduction step the lower zirconium halides formed may be dissolved in water or dilute mineral acid to obtain solutions of zirconium oxyhalides containing less than 0.1 per cent of hafnium. The halide preferred is the chloride. |
| priorityDate | 1953-06-03-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 31.