Magnetic field enhanced cake-filtration solid-liquid separations

• US 8,119,010 B2
• Filed: 02/17/2005
• Issued: 02/21/2012
• Est. Priority Date: 02/17/2004
• Status: Expired due to Fees

• 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: Keller, Karsten, Rey, Christopher M., Fuchs, Benjamin, Hoffmann, Christian
• Primary Examiner(s): Reifsnyder, David A
• Application Number:
  US11/060,001
• Publication Number:
  US 20050252864A1
• Time in Patent Office: 2,560 Days
• Field of Search: 210/695, 210/702, 210/767, 210/771, 210/800, 210/806, 210/223, 204/554, 204/557, 204/660, 204/664
• 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. A process for the separation of magnetic particles from a solid-liquid mixture that resides in a container that comprises a filter, comprising

(a) subjecting the solid-liquid mixture in the container to a homogeneous magnetic field, a magnetic field gradient or both and

(b) subjecting the solid-liquid mixture in the container to pressure to form a filter cake on the filter in the container.

2. A process according to claim 1 wherein steps (a) and (b) are performed simultaneously.

3. A process according to claim 1 wherein step (a) is performed separately and prior to step (b).

4. A process according to claim 1 wherein step (a) is performed both separately and prior to, and simultaneously with, step (b).

5. A process according to claim 1 wherein a magnetic field is oscillating.

6. A process according to claim 1 wherein the step of subjecting the mixture to pressure comprises a step of subjecting the mixture to mechanical pressure, gas pressure, hydrostatic pressure, hydrodynamic pressure, gravitational pressure, or a combination thereof.

7. A process according to claim 1 wherein the step of subjecting the mixture to pressure comprises a step of subjecting the mixture to gas pressure.

8. A process according to claim 1 wherein the step of subjecting the mixture to pressure comprises a step of subjecting the mixture to air pressure.

9. A process according to claim 1 wherein the field strength of a homogeneous magnetic field is ≧

0.01 T.

10. A process according to claim 1 wherein a magnetic field gradient has a magnitude ≧

1 T/m.

11. A process according to claim 9 wherein a magnetic field gradient has a magnitude ≧

1 T/m.

12. A process according to claim 1 wherein a homogeneous magnetic field is perpendicular to the direction of the pressure.

13. A process according to claim 1 wherein a homogeneous magnetic field is parallel to the direction of the pressure.

14. A process according to claim 1 wherein a homogeneous magnetic field is anti-parallel to the direction of the pressure.

15. A process according to claim 1 wherein the magnetic force provided by a magnetic field gradient is parallel to the direction of the pressure.

16. A process according to claim 1 wherein the magnetic force provided by a magnetic field gradient is anti-parallel to the direction of the pressure.

17. A process according to claim 1 wherein the magnetic particles comprise functionalized magnetic beads attached to biological materials.

18. A process according to claim 1 wherein the filter comprises nylon.