MAGNETIC SEPARATION

• Main Authors: WATSON, JAMES H. P, CLARK, NORMAN O
• Format: Patent
• Language: English; French
• Published: 22.08.1978
• Subjects: MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLIDMATERIALS OR FLUIDS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROMSOLID MATERIALS OR FLUIDS; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS; SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATICTABLES OR JIGS; TRANSPORTING

CONTINUOUS MAGNETIC SEPARATION OF WEAKLY MAGNETISABLE PARTICLES A magnetic field is established in a predetermined zone. A quantity of fluid, from which native weakly magnetisable particles are to be separated, and magnetisable material is passed into the predetermined zone. The fluid and the magnetisable material are caused to flow substantially together through that zone in a predetermined direction. The fluid is discharged from that zone after it has been in the zone for a sufficient time to enable native magnetisable particles to be magnetised and attracted to the magnetisable material. The native magnetisable particles are carried by the magnetisable material out of the fluid within that zone, and are then discharged from the zone downstream of the discharge of the fluid. The native magnetisable particles are removed from the magnetisable material by flushing and degaussing. In a particular form of the invention, foreign magnetisable material (which is relatively large in relation to the native magnetisable particles) is added to the fluid prior to the fluid being passed into the predetermined zone by means of a chain which is moved by the action of the fluid and particles on transverse members on the chain. A rotating magnetic field is used to agitate the particles in the fluid prior to being passed into that zone. The native magnetisable particles are magnetised and attracted to the foreign magnetisable particles and these are in turn attracted to magnetisable spikes or fin-like projections on the chain within that zone. The native and foreign magnetisable particles are then removed from that zone on the chain.