Process for producing high-purity coal
US4134737A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 2, 1976 |
| Grant date | Jan 16, 1979 |
| Priority date | — |
| Expiry date | Feb 2, 1996 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10L9/02
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
High-purity coal useful in the production of high-purity carbon is produced by treating coal to remove the impurities therein. The coal, which may be subject to conventional pretreatment processes such as beneficiation processes or the like, digested in a caustic solution to solubilize certain of the impurities in the coal and to chemically react with other impurities to form acid soluble products. The digested coal is then filtered to separate the partially purified coal from the caustic and soluble impurities dissolved therein. The coal is then treated with a mineral acid to dissolve the acid soluble products contained in the coal. Finally, the coal is subjected to a nitric acid treatment to remove metal sulfides. The resultant high-purity carbon contains less than 0.1% by weight ash or metal sulfides.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.