Magnetic separator

Claim 1

A PROCESS FOR SEPARATING PARTICLES OF A SOLID MATERIAL HAVING AT LEAST A PREDETERMINED MAGNETIC SUSCEPTIBILITY FROM A MIXTURE OF SAID PARTICLES WITH OTHER SOLID PARTICLES HAVING A LOWER MAGNETIC SUSCEPTIBILITY, SAID PROCESS COMPRISING: HELICALLY DEVELOPING A FLOW OF MULTI-PHASE ALTERNATING CURRENT AROUND A TUBULAR SPACE WHEREBY TO FORM AND MAINTAIN WITHIN SAID TUBULAR SPACE A MAGNETIC FIELD CHARACTERIZED BY A PLURALITY OF PLANAR NORTH AND SOUTH POLES ALTERNATELY DISPOSED TRANSVERSELY TO THE LONGITUDINAL AXIS AND SUBSTANTIALLY ACROSS THE WHOLE CROSS SECTION OF SAID TUBULAR SPACE, SAID MAGNETIC FIELD HAVING A SUFFICIENT FLUX DENSITY EFFECTIVELY TO MAGNETIZE SAID PARTICLES OF SOLID MATERIAL HAVING AT LEAST SAID PREDETERMINED MAGNETIC SUSCEPTIBILITY: FORMING A SUSPENSION OF SAID MIXTURE IN FLUID VEHICLE: INTRODUCING SAID SUSPENSION AND ADVANCING THE SAME ALONG A FIRST PATHWAY WITHIN SAID TUBULAR SPACE AND EXTENDING LENGTHWISE THEREOF, ADVANCING SAID POLES STEPWISE ALONG SAID TUBULAR SPACE WHEREBY THE PARTICLES OF MATERIAL WITHIN SAID SUSPENSION WHICH ARE EFFECTIVELY MAGNETIZED ARE ADVANCED ALONG SAID FIRST PATHWAY UNDER THE INFLUENCE OF THE STEPWISE ADVANCEMENT OF SAID POLES: DISCHARGING SAID SUSPENSION FROM SAID FIRST PATHWAY INTO SAID TUBULAR SPACE: WITHDRAWING ALONG A SECOND PATHWAY WITHIN SAID TUBULAR SPACE SAID FLUID VEHICLE AND SUSPENDED SOLID MATERIAL WHICH IS NOT EFFECTIVELY MAGNETIZED AND SUBSEQUENTLY COLLECTING SUCH MATERIAL: AND CONTINUING TO ADVANCE SAID EFFECTIVELY MAGNETIZED PARTICLES WITHIN SAID TUBULAR SPACE UNDER THE INFLUENCE OF THE STEPWISE MOVEMENT OF SAID POLES TO A POINT OF COLLECTION AND COLLECTING THE SAME.