Integrated coal cleaning process with mixed acid regeneration
US4695290A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1985 |
| Grant date | Sep 22, 1987 |
| Priority date | — |
| Expiry date | Jun 24, 2005 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10L9/02
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The present invention provides processes for the continuous removal of contaminants from coal to produce a clean purified fuel. The processes generally comprise producing a clean coal product having a mineral matter content of less than about 5 percent by weight from coal and coal derivatives by leaching feed coal crushed or sized to less than about 1 inch with a mixture of hydrochloric and hydrofluoric acids comprising less than about 70 weight percent HF and less than about 38 weight percent HCl at atmospheric pressure and at a temperature below the boiling point of the acid mixture. One embodiment of the present invention provides a process for producing a coal product with 5 percent ash content or less comprising comminuting raw coal or other coal-derived feed material to a size less than about 10 mm; leaching the comminuted coal with a mixture of HF and HCl comprising less than about 70 percent by weight HF and less than 38 percent by weight HCl at atmospheric pressure and a temperature below boiling, preferably ambient; separating the leached residue from the spent acid; washing the leached residue substantially free of spent acids and dissolved solids; separating pyrite from…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.