http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-1119843-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_4a195182bd6e8e3556486f9c74a2dfec |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C01G41-00 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C01G41-00 |
| filingDate | 1965-07-01-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1968-07-17-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-1119843-A |
| titleOfInvention | Process and apparatus for converting waste tungsten into ammonium tungstate solution or crystalline ammonium paratungstate by means of electrolysis |
| abstract | <PICT:1119843/C6-C7/1> Scrap tungsten is subjected to anodic dissolution in an aqueous solution of ammonia containing at least 10 g/1 of free ammonium hydroxid at a current density of 5 to 20 amps/1 until a concentration of 200 to 300 g/1 of ammonium tungstate is obtained. Part, e.g. 60 to 70% by volume, of the ammonium tungstate solution may be removed and evaporated to obtain ammonium paratungstate crystals. The free ammonium hydroxide concentration may be adjusted by introducing either concentrated solution or preferably gaseous ammonia. To increase the conductivity of the electrolyte there may be added tungstic acid, ammonium chloride, nitrate or carbonate, or carbon dioxide may be bubbled into the bath. To depassivate the anode surface hydrogen peroxide may be added to the bath to oxidize impurities in the scrap, metal impurities including molybdenum, being cathodically deposited together with some tungsten. Typically the process is performed in a closed cell having an inlet tube 6 for ammonia gas or solution, a suction tube 7 for the removal of electrolytically released hydrogen and ammonia, a thermometer and anode baskets 2 for the tungsten scrap, e.g. as balls of scrap wire, formed of tubes 8 through which a cooling liquid is passed to maintain a bath temperature of 40 to 50 DEG C. 80 to 95% of the anode basket surface may be coated with an insulating material to protect it from erosion. Preferably the anode baskets and the cathodes 3 arranged on both flanks of each basket are made of metal resistant to ammonia. In an alternative arrangement both cathode and anode are in the form of baskets containing scrap tungsten and the polarity is reversed every third to fifth minute. |
| isCitedBy | http://rdf.ncbi.nlm.nih.gov/pubchem/patent/CN-115159576-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-3936362-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/CN-116495784-B http://rdf.ncbi.nlm.nih.gov/pubchem/patent/CN-116495784-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/CN-109368661-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/CN-109052477-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-4283257-A |
| priorityDate | 1964-07-06-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 45.