http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-954088-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_7294b2961b3ffcc27db601f8c6e39738 |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C01F7-57 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C01F7-57 |
| filingDate | 1961-08-04-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1964-04-02-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-954088-A |
| titleOfInvention | Process of preparing aluminium chlorhydroxides and aluminium hydroxide |
| abstract | <PICT:0954088/C3/1> Process and apparatus for preparing aluminium chlorhydroxides and aluminium hydroxide by electrolysing an aqueous solution of aluminium chloride as catholyte in a compartment cell, thereby liberating hydrogen at the cathode; intercepting chloride ions migrating towards the anode in a middle compartment and reacting such ions with aluminium oxide to form aluminium chloride; the anolyte comprising a dilute solution of a strong acid allowing evolution of oxygen only at the anode. The process may be used to form aluminium chlorhydroxides; Al2(OH)nCl6-n, n=1 to 5; and aluminium hydroxide i.e. for Al2(OH)2Cl4, Al2(OH)3Cl3, Al2(OH)4Cl2, Al2(OH)5Cl, Al(OH)3; and mixtures of these can also be obtained. The electroylsis proceeds down the series and can be followed by observing the pH of the reaction mixture which ranges from about 1 at the start to about 4.4, with aluminium hydroxide formed as a precipitate at the close of the electrolysis. The consumption of hydrogen chloride in the middle compartment is related to the salt or salts produced. The diaphragm cell has a carbon cathode 2 in the cathode compartment 1, and a platinum anode 4 in the anode compartment 3; the intermediate compartment 5 is separated from the catholyte and anolyte by diaphragms 6 and 7. The anolyte is an aqueous acid whose anion is not discharged as a gas at the anode, and a 0.5-10% solution of sulphuric acid is satisfactory. It is preferred that diaphragm 7 be of cation-permselective membrane material and so not pass chlorine ions and exclude chlorine ions entirely from the anode compartment, inasmuch as these ions in the anolyte could be discharged at the anode as chlorine gas reducing the yield. Suitable types of permselective membranes are detailed. Catholyte reaction is favoured by electrolysis at a temperature above 70 DEG C.: the upper temperature limit is determined by the boiling point of the catholyte and is usually about 100 DEG C. Reaction in the intermediate compartment proceeds above 70 DEG C. Chloride ion migration from the intermediate compartment into the anode compartment is less at low temperatures and it is preferred that the anolyte be kept as close to room temperature as is convenient, about 30-35 DEG C. in examples quoted: also ion-permselective membranes tend to become less efficient as temperature increases. The desired temperature gradient from catholyte to anolyte can be achieved by cooling coils in the intermediate compartment adjacent to diaphragm 7. |
| priorityDate | 1960-09-06-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 36.