Abstract: In a process for reducing the sulfur and ash contents of coal, coal is sequentially contacted with fused alkali metal caustic, wash water, and acid. Contacting the coal with the caustic produces water-soluble compounds. Sufficient wash water is used to reduce the temperature of the caustic treated coal and dissolve the bulk of the water-soluble compounds before the water-soluble compounds convert to water-insoluble compounds that precipitate on the caustic-treated coal. Caustic removed from the coal by the water is recovered as anhydrous caustic for again contacting coal.

Abstract: In a process for reducing the sulfur and ash contents of coal, coal is sequentially contacted with fused alkali metal caustic, water, carbonic acid, and a strong acid. Caustic removed from the coal by the water and the carbonic acid is recovered as anhydrous caustic for again contacting coal.

Abstract: A crushed hydrocarbon-bearing material containing hydrocarbon and foreign mineral constituents is dispersed in fused alkali metal caustic to remove the sulfur content and release the foreign mineral matter from the hydrocarbon material for recovery and/or upgrading of the hydrocarbon content. The process permits recovery of 80-95% of the available kerogen or other hydrocarbon in a mineral matrix such as oil shale rock and conditions a solid fossil fuel such as coal, as well as the kerogen or other hydrocarbon released from the mineral matrix, for removal of substantially all remaining ash and other foreign mineral matter by subsequent washing of the hydrocarbon product in an aqueous solution of acid.

Abstract: A method for removing ash, sulfur and inertinite from crushed coal includes float/sink treatment in aqueous solutions of monosaccharides, disaccharides, hydrogenated monosaccharides, hydrogenated disaccharides and mixtures thereof. Such solutions also improve the performance of such heavy media physical cleaning equipment as cyclones, heavy media baths, tables, spirals, hydroclones, flotation cells, jigs and solid-bowl centrifuges.