A beneficiation process to produce low ash clean coal from high ash coals, including: preparing a coal slurry from fine coal and water and discharging it to a first reactor; preparing an alkali solution and discharging it to a first reactor; carrying-out a leaching reaction 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 and delivering it to a second reactor; preparing a diluted alkali solution 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.