The results of МО-212 jigging machine operating regimes optimization studies in commercial processing of the Catoca (Angola) deposit ores fine grained size fractions are described. A possibility of using the methods of sink and float testing in gravity solutions on separation products samples of relatively small mass, with regard to the studies in question, is shown. МО-212 jigging machine maximum throughput rate has been determined at the level of 60 t/hr.