6. A PROCESS FOR IMPROVING THE SELECTIVE FLOTATION OF SLIMED APATITE FROM SLIMED CLAYEY GANGUE IN A MINUS 325 MESH, TYLER STANDARD, AQUEOUS ORE PULP CONTAINING A SUBSTANTIAL QUANTITY OF COLLOIDAL SLIMES WHICH COMPRISES INCORPORATING PLUS 325 MESH, TYLER STANDARD, HARD INERT GRINDING MEDIUM INTO SAID ORE PULP AND PARTIALLY FILLING A HORIZONTAL BAFFLE-FREE CYLINDRICAL DRUM HAVING A SMOOTH INNER SURFACE WITH SAID PULP AND SAID GRINDING MEDIUM, ROTATING SAID DRUM ABOUT ITS HORIZONTAL AXIS AT A SPEED SUCH THAT SAID PULP WITHIN THE DRUM IS IN THE FORM OF A POOL OCCUPYING SUBSTANTIALLY ONLY THE LOWER PORTION OF THE DRUM AND THE INDIVIDUAL PARTICLES OF GRINDING MEDIUM TRAVEL IN CONTINUOUS GENERALLY ELLIPITCAL PATHS WITHIN THE PULP CONTINUING SAID ROTATION FOR AT LEAST 10 MINUTES TO PRODUCE A PARTICLE SIZE REDUCTION OF SAID ORE PULP, SEPARATING SAID GRINDING MEDIUM FROM SAID PUPL AND SUBJECTING SAID PULP TO FROTH FLOTATION IN THE PRESENCE OF A COLLECTOR REAGENT SELECTIVE TO SAID APATITE.