Abstract: A cyclical and automatable process and apparatus for continuously removing undesired components from solid particles by means of a solvent, the process including maintaining an expanded bed of solid particles in a vertical column, supplying a suitable solvent to the bed to flow through the bed either upwardly or downwardly in a selectably alternating manner, supplying solid particles to the top of the column while the solvent flows upwardly therethrough and interrupting the supply of solid particles and removing a bottom portion of the bed by the solvent when it flows downwardly.