Coal extraction
US4997548A · kind A · utility
12Cited by
1References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 8, 1988 |
| Grant date | Mar 5, 1991 |
| Priority date | — |
| Expiry date | Aug 8, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10G31/06
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Recycled oil solvents for coal extraction have their content of saturated cyclic species reduced by thermal cracking at 470.degree. to 540.degree. C. for a few minutes, restoring their effectiveness as solvents for coal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.