1. THE IMPROVEMENT IN THE CONCENTRATION OF SYLVITE FROM POTASH ORES CONTAINING SYLVITE IN ASSOCIATION WITH MINOR BUT OBJECTIONABLE AMOUNTS OF CLAY AND SIMILAR SLIME-FORMING CONSTITUENTS, WHICH COMPRISES GRINDING THE ORE TO WITHIN THE MAXIMUM SIZE RANGE DESIRED FOR THE SEPARATION TREATMENT, SUSPENDING THE ORE IN A SATURATED AQUEOUS BRINE SOLUTION OF THE SOLUBLE ORE CONSTITUENTS, ADDING A LIGNOSULFONATE IN AN AMOUNT SUFFICIENT TO DISPERSE THE SLIME-FORMING CONSTITUENTS IN THE RESULTING PULP, AGITATING THE PULP UNDER SCRUBBING CONDITIONS TO FREE THE SURFACES OF THE SYLVITE PARTICLES FROM OCCLUDED SLIME PARTICLES, ADDING ADDITIONAL BRINE TO DILUTE THE PULP