| 摘要 |
619,918. Washing coal and ores. CHAPMAN, W. R. Dec. 2, 1946, No. 35718. [Class 82(ii)] Impurities are separated from coal, ores and like water-insoluble minerals by froth flotation in a liquid medium which has a specific g r a v i t y greater than 1.05 and less than the specific gravity of the materials from which the impurities are tc be separated. The medium may be a solution or a suspension of the tailings of the process or a substance such as barytes, magnetic sand, boiler or blast furnace Hue dust or ferro-silicon in a liquid. As shown, raw coal with some of the medium may be mixed with flotation reagent in a tank b and added with or without more medium to a flotation cell a the clean coal passing out of the apparatus at c and the tailings passing to a concentrator e from which all or part may be recirculated with or without classification to the flotation process. In a modification, Fig. 2 (not shown), the coal may be screened, the undersize being subjected to froth flotation in water and the oversize to froth flotation in a medium composed of a suspension of the tailings after thickening from either or both of the flotation steps. |
