Coal extraction
US4487682A · kind A · utility
1Cited by
4References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 23, 1980 |
| Grant date | Dec 11, 1984 |
| Priority date | — |
| Expiry date | Jun 23, 2000 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10G1/045
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Coal extracts from hydrogenative liquid extraction of coals can be more easily and more quickly filtered if the extraction is carried out at a temperature over 420.degree. C. and the resulting extract is fractionated using a cut point in the range 200.degree. to 300.degree. C. to remove low boiling material. The product is then filtered to give a filtrate containing less than 0.1% by weight of mineral matter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.