A method for obtaining treated coal and silica from fly ash containing coal.

摘要

A method for treating mixtures of solid carbon and fly ash (23), the metal oxides, silicon dioxide and sulfur compounds, to produce treated coal (38) and substantially pure silica (45) comprising first reacting a mixture of the coal and fly ash with hydrogen fluoride (23) in water for producing a liquid stream (27), the silicon fluoride and metal fluorides, and includes a solid stream (29), the unreacted carbon and sulfur compounds; 2. reacting the sulfur compounds dissolved in water metal nitrates to form an aqueous solution (31) of nitrate, metal and sulfur ions; 3. separating the aqueous solution (31) of nitric acid, sulfuric acid and metal ions from the solid carbon (38); 4. Wash the previously treated coal (38) with water; 5. reacting the silicon fluorides and metal fluorides with metal nitrates in an aqueous mixture to the forming of solid silicon dioxide (45), and separating the solid silica from the aqueous mixture.