A hydraulic system for separating fine particles according to magnetic susceptibility

Particles suspended in a fluid carrier are separated by first, grading into fractions of equal settling rates and, second, separating the equal settling particles according to their magnetic susceptibilities. The particulate sample to be separated is passed through a two-path parallel flow system. In one path, the sample is selectively graded, by elutriation into equal-settling fractions. Each such fraction then flows directly to the second path, where it passes through an isodynamic magnetic field at a velocity proportional to its settling rate. Such proportionality between settling velocity and flow velocity provides a residence time which ensures that the degree of deflection, recovery of the more magnetic particles, on the one hand and the less magnetic particles on the other hand, will be attained within the active length of the magnetic field.