An empirical model of the Kelsey Centrifugal Jig is presented. The model describes the partition of feed material to the jig concentrate, taking account of the main jig operating parameters: g-force, ragging characteristics and stroke length and of the material properties of the feed. The model has been tested against the laboratory-scale jig separation of tungsten slime tailings. The effect of changing the jig ragging was predicted. The model has been used in the design of a wolframite tailings retreatment plant.