A previous investigation carried out by the authors at the Hellyer concentrator, using a 3 m(3) cell fitted with four different impellers treating plant zinc cleaner feed ore, suggested a linear correlation between flotation Tate constant k and bubble surface area flux S-b The relationship between k and S-b was found to be independent of impeller type. This paper describes an investigation at the Scuddles concentrator in Western Australia to validate the findings at Hellyer for a different ore. Unlike the Hellyer work for which only one froth depth was used the Scuddles work was carried out at different froth depths using the same 3 m(3) cell fitted in turn with three different impellers viz Batequip, Dorr-Oliver and Outokumpu. The results confirmed the strong correlation between k and S-b at three different froth depths used far the study. Moreover, this relationship was found to be practically independent of impeller type. However, at shallow froth depth-the k-S-b relationship was found to be linear whereas at intermediate and deep froth depths the relationship was found to be non-linear with the froth playing an important role in the overall kinetics.