Abstract: The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other minerals particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal.

Abstract: A process for preparing a coal-water fuel from a low rank coal. The first step of the process provides for an aqueous slurry containing particles of the low rank coal. A quantity of an agglomerating agent in the range of about 10% to 30% weight to dry ash - free low rank coal weight is added to the slurry to produce a mixture. The mixture is then agitated to form agglomerates. Following separation of the agglomerates, the agglomerates are contacted with steam or an inert gas having a temperature in the range of about 250.degree. C. to 420.degree. C. at substantially atmospheric pressure to produce partially deoiled agglomerates containing less than about 7% by weight of residual bridging liquid and having a moisture capacity reduced by a factor of at least about 2.5 at a relative humidity of 96% compared to the moisture capacity of the low rank coal.

Abstract: The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other minerals particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal.

Abstract: A process for removing oil from coal fines that have been agglomerated or blended with heavy oil comprises the steps of heating the coal fines to temperatures over 350.degree. C. up to 450.degree. C. in an inert atmosphere, such as steam or nitrogen, to convert some of the heavy oil to lighter, and distilling and collecting the lighter oils. The pressure at which the process is carried out can be from atmospheric to 100 atmospheres. A hydrogen donor can be added to the oil prior to deposition on the coal surface to increase the yield of distillable oil.

Abstract: The process involves adding a low quality oil to an aqueous slurry of sub-bituminous coal particles to act as a selective agglomerating agent. When the mixture is agitated, as by pumping it through a pipeline loop, the coal particles agglomerate and may later be separated from the minerals by screening. The low quality oil used is selected from the group consisting of bitumen, heavy oil, and emulsions thereof. In a preferred aspect, a light hydrocarbon diluent, selected from the group consisting of kerosene, naphtha, and diesel oil, is added to improve the agglomeration results.

Abstract: A three step process is provided for producing high strength metallurgical coke from high volatile caking coals. Firstly, the caking coal is oxidized by heating the coal in an oxygen-containing atmosphere for a period of time. Secondly, the oxidized caking coal is blended with fresh or relatively non-oxidized caking coal. Thirdly, the blend is carbonized to yield metallurgical grade coke.