plates in the magnetic field prevent the need for increased ampere turns as compared to known inductive matrices for example those consisting of grooved plates expanded metal or balls then the magnetic material retained in the matrix is cleaned in the magnetic field by a wash liquid or compressed air and an intermediate product is collected underneath the matrix the polarization particle chains then decompose without an external magnetic field in the remanent magnetic field of the soft magnetic plates the gradients generated by the magnetic particles themselves and thus the inter article interaction forces as well as the dipole image forces are so small that they can no longer stabilize the polarization particle chains or retain them between the plates external field gradients are likewise avoided due to the smooth plate shaped induction bodies thus ferromagnetic and ferrimagnetic particles also are not retained in the matrix when flushing without a magnetic field the magnetic product is completely discharged by the flush liquid or compressed air the invention is disclosed in more detail below with reference being had to the sole figure of the drawing the figure shows in partial cross section the structure of a matrix made of soft magnetic plates the armature or matrix of the present invention is composed of the soft magnetic plates 1 each of which suitably comprises a corrosion free homogeneous chrome steel sheet the spacing between the plates 1 is maintained by perforated disks 2 made of aluminum aluminum rods are used as the connecting elements 3 of the matrix they extend through aligned holes in the plates 1 as well as through the perforated disks 2 and are riveted at both ends the outer.