Abstract: Mixer-settler apparatus of the reverse liquid flow type having at least one assembly which includes one or more mixers in series, each being fitted with stirrers and pumps, at least one settling tank in which liquids separate, and at least one submerged chute extending into the settling tank from a pump to convey the mixture of liquids from the pumps to the settling tank. The chute is constructed of enlarged dimensions which extend over a major portion of the width of the tank to facilitate a pre-settling action within the chute, and the chute extends a substantial distance into the settling tank to allow extended pre-settling time.