Method and magnetic separator for removing weakly magnetic particles from slurries of minute mineral particles

摘要

A method and a magnetic separator are disclosed particularly for the removal of particles of low magnetic susceptibility, present usually as impurities and often largely of submicron sizes, from aqueous slurries of clay or other minute mineral particles. A high intensity magnetic field is established between vertically spaced pole members in the general direction of flow of the slurry through a canister disposed between confronting surfaces of the pole members, the canister being packed with multitudinous elongate ferromagnetic elements which present surface irregularities with each contacting, yet also spaced from others, so as to constitute a flux conductive matrix that diverts the slurry flow into diverse courses and concentrates the flux at myriad points therein. With the magnetic field being applied, the slurry flow is continued until the collecting of weakly magnetic particles onto the matrix elements has diminished substantially, whereupon residual slurry may be rinsed from the canister by a gentle flow of water. Then the magnetizing of the matrix is discontinued and water is forced through the matrix to flush collected particles out of the canister.