Method and appratus for extracting tar sand

patentMethod and apparatus for separating coarse sand particles from fine sand particles in a slurry of sand and a solution such as results from the solvent extraction of tar sand, such method comprising causing flow of such slurry in a generally horizontal direction and then causing upward flow at a rate such that coarse particles settle out and fine particles move upwardly to a slurry outlet. The apparatus preferably comprises a tubular duct for downward flow, bottom openings in the duct for outward flow, a lower receptacle for coarse particles and an annular space surrounding the duct for upward flow of slurry of solution and fine sand particles