Magnetic field enhanced cake-filtration solid-liquid separations

• US 20050252864A1
• Filed: 02/17/2005
• Published: 11/17/2005
• Est. Priority Date: 02/17/2004
• Status: Active Grant

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Fuchs, Benjamin, Hoffmann, Christian, Rey, Christopher M., Keller, Karsten
• Granted Patent: US 8,119,010 B2
• Time in Patent Office: Days
• US Class Current: 210/695
• CPC Class Codes: B01D 35/06 Filters making use of electricity or magnetism ultrafiltration, microfiltration B01D61/14; electrodialysis, electro-osmosis B01D61/42; devices comprising filters and magnetic separators B03C1/30
• CPC Class Codes: B01D 37/00 Processes of filtration processes specially adapted for filtering gases B01D46/00
• CPC Class Codes: B03C 1/034 characterised by the matrix elements
• CPC Class Codes: B03C 1/30 Combinations with other devices, not otherwise provided for
• CPC Class Codes: B03C 2201/18 Magnetic separation whereby the particles are suspended in a liquid

Abstract

This invention relates to an improved cake-filtration solid-liquid separation process wherein the improvement comprises simultaneously subjecting the solid-liquid mixture to a homogeneous magnetic field, a magnetic field gradient or both and cake-filtration to accomplish separation.

Claims

1. An improved process for cake-filtration solid-liquid separation of a solid-liquid mixture containing magnetic particles, the improvement comprising simultaneously subjecting the solid-liquid mixture to a homogeneous magnetic field, a magnetic field gradient or both and the mechanical means used to provide the pressure needed to drive the cake-filtration process.

2. The improved process of claim 1, wherein said mechanical means is selected from the group consisting of mechanical pressure, gas pressure, hydrostatic pressure, hydrodynamic pressure, gravitational pressure, or a combination thereof.

3. The improved process of claim 2, wherein said mechanical means is gas pressure.

4. The improved process of claim 1, the improvement comprising simultaneously subjecting the solid-liquid mixture to a homogeneous magnetic field and said mechanical means, wherein the field strength of said homogeneous magnetic field is ≧

0.01 T.

5. The improved process of claim 1, the improvement comprising simultaneously subjecting the solid-liquid mixture to a magnetic field gradient and said mechanical means, wherein said magnetic field gradient has a magnitude ≧

1 T/m.

6. The improved process of claim 1, wherein the field strength of said homogeneous magnetic field is ≧

0.01 T and said magnetic field gradient has a magnitude ≧

1 T/m.

7. The improved process of any of claims 4-6, wherein said mechanical means is selected from the group consisting of mechanical pressure, gas pressure, hydrostatic pressure, hydrodynamic pressure, gravitational pressure, or a combination thereof.

8. The improved process of claim 7, wherein said mechanical means is gas pressure.

9. The improved process of claim 8, wherein said mechanical means is air pressure.

10. The improved process of any of claims 1, 2, 4 or 6, wherein said homogeneous magnetic field is perpendicular to, parallel to or anti-parallel to the direction of the pressure provided by said mechanical means.

11. The improved process of any of claims 1, 2, 5 or 6, wherein the magnetic force provided by said magnetic field gradient is parallel to or anti-parallel to the direction of the pressure provided by said mechanical means.

12. An improved process for cake-filtration solid-liquid separation of a solid-liquid mixture containing magnetic particles, the improvement comprising subjecting the solid-liquid mixture to a homogeneous magnetic field, a magnetic field gradient or both prior to the cake-filtration separation process to promote agglomeration of the magnetic particles.

13. The improved process of claim 12, the improvement comprising subjecting the solid-liquid mixture to a homogeneous magnetic field prior to the cake-filtration separation process to promote agglomeration of the magnetic particles.

14. The improved process of claim 12 or 13, wherein the cake-filtration separation process comprises subjecting the solid-liquid mixture to a homogeneous magnetic field, a magnetic field gradient or both in conjunction with the mechanical means used to provide the pressure needed to drive the cake-filtration process.

15. The improved process of claim 14, wherein said mechanical means is selected from the group consisting of mechanical pressure, gas pressure, hydrostatic pressure, hydrodynamic pressure, gravitational pressure, or a combination thereof.