Abstract: This invention relates to a cyclone for dense medium separation that includes an inverted conical shaped cyclone body which provides an interior space having an inner wall surface a vortex finder including a lower end that extends longitudinally into an upper region of the interior space of the cyclone body an overflow outlet associated with an upper end of the vortex finder a feed inlet that is in fluid communication with the upper region of the interior space of the cyclone body an outlet associated with a lower region of the interior space and the inner wall surface of the interior space curves inwardly and downwardly from the upper region curves inwardly and downwardly from the upper region of the interior space to the lower region of the interior space.

Abstract: An improved beneficiation process to produce low ash clean coal from high ash coals, comprising: preparing a coal slurry from fine coal and water and discharging it to a first reactor; preparing an alkali solution of NaOH and water and discharging it to a first reactor; carrying-out a leaching reaction between the coal and the alkali solution inside the first reactor; transferring the reaction mixture to a second reactor for filtration and washing to produce a filter cake; preparing a diluted acid solution in a second tank and delivering it to a second reactor; preparing a diluted alkali solution in a third tank and delivering it to a second reactor; feeding a coal slurry prepared from the filter cake into the second reactor for washing and transferring to a second filtration unit; transferring the product after filtration to a third reactor; carrying-out different leaching reaction sequences in the first, second, and third reactors; and transferring to a fifth tank the treated coal filter cake for drying.

Abstract: This invention relates to a cyclone for dense medium separation that includes an inverted conical shaped cyclone body which provides an interior space having an inner wall surface a vortex finder including a lower end that extends longitudinally into an upper region of the interior space of the cyclone body an overflow outlet associated with an upper end of the vortex finder a feed inlet that is in fluid communication with the upper region of the interior space of the cyclone body an outlet associated with a lower region of the interior space and the inner wall surface of the interior space curves inwardly and downwardly from the upper region curves inwardly and downwardly from the upper region of the interior space to the lower region of the interior space.