Abstract: A body of liquid containing charged particles is caused to flow in a stream. High level turbulence in the stream is preferably removed by a baffle in the path of the stream. The stream is then subjected to a magnetic field rotating normal to the general flux of the stream that is of sufficient strength to cause a substantial portion of the charged particles in the stream to move in respective convoluted paths generally centered around the axis of the field's rotation. Immediately downstream from the rotating magnetic field is a second magnetic field having lines of force generally parallel to the general flux of the stream. The second magnetic field is of sufficient strength to cause the rotating charged particles to move in a spiral motion toward the flux axis of the stream. The length of this second magnetic field is sufficient, in light of the flow rate of the liquid, to allow a substantial portion of the spiraling charged particles to enter a sub-stream at the core of the stream.