For an effective separation of more than one kind of particle from a mixture, a plurality of separation stages are provided, arranged in series. Mixer elements may be disposed along the flow path to disturb the sedimenting particles, to release entrained lighter particles. Further, the separation channel may widen near the particle recovery port(s), to well suspend lighter particles in the fluid as denser particles are extracted and/or to allow gravitational forces to more effectively influence particle movement. In an example embodiment one stage utilizes Coriolis force in a narrow, radial passage for concentrating and agglomerating particles. The serial separation stages may be communicated with a radially inward extending passage to limit undesirable particle spill-over.
