http://rdf.ncbi.nlm.nih.gov/pubchem/patent/CA-2368699-C
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_e5da6ef53611e1dc8d00f716dd53c028 |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C01B25-234 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C01B25-234 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C01B25-18 |
| filingDate | 2000-03-23-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| grantDate | 2008-11-25-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| inventor | http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_0f5bf11b0ca3126b2015a5fcf38c30ee http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_2859dce740eec484091d9b4862d28b27 http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_fe22d3759c7bf99bf1d97bf285a8a53d http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_f7b804d735641e8c79ead4484ab4cb1e |
| publicationDate | 2008-11-25-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | CA-2368699-C |
| titleOfInvention | Process for production of phosphoric acid by crystallisation of phosphoric acid hemihydrate |
| abstract | The invention relates to a process for producing simultaneously food-grade and fodder-grade phosphoric acid by crystallizing phosphoric acid hemihydrate, × 0.5 H2O, from a prepurified feed acid, which is purified and crystallized with the help of the following steps, a) after the step of froth-flotation of phosphate concentrate, the concentrate is directed to a strongly magnetic separation step in order to decrease the Mg ion amount, b) the phosphate concentrate is leached in a mixture of sulfuric acid and phosphoric acid according to the wet process, the precipitated SO4 and As ions are removed, and a silicon source is added in order to adjust the F/Si molar ratio to < 6, c) the phosphoric acid is concentrated, the solids precipitate is removed, and the F ions are evaporated, d) the feed acid obtained from step c, having a concentration of > 58% P2O5, solids concentration of < 0.05%, Mg ion concentration of < 1.5%, SO4 ion concentration < 1%, As ion concentration of < 8 ppm and F ion concentration of < 0.2%, is crystallized at a steady crystal growth rate of < 10 µm/min, the temperature difference in the first crystallization being < 17°C, and the crystals are washed with the undersaturated mother liquor of the subsequent recrystallization step, e) the phosphoric acid crystallized in step d is melted, is diluted to a concentration of < 63% P2O5, seed crystals are added, and crystallization is carried out as in step d, the temperature difference being < 8°C, and the crystals are washed with an undersaturated solution of phosphoric acid, and f) optionally the phosphoric acid crystallized in step e is melted, is diluted to a concentration of < 63% P2O5, seed crystals are added, and crystallization is carried out as in step d, the temperature difference being < 6°C, and the crystals are washed with an undersaturated washing solution prepared from product crystals. |
| priorityDate | 1999-03-24-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 34.