By Greg Fenrick

According to InfoMine’s Dictionary, filter cake has two definitions:

  • The layer of concentrated solids from the drilling mud left behind on the walls of a borehole, or on a filter paper in filtration tests on mud. (Source: Inst. Petrol).
  • The compacted solid or semisolid material separated from a liquid and remaining on a filter after pressure filtration (Source: Inst. Petrol).

In oil well drilling, the filter cake serves two purposes, one to prevent the walls of the hole from collapsing and second to prevent fluid loss in porous formations. In mineral mining, the filter cake is what’s leftover after a slurry is dewatered, which is then removed for further purification.

There are only a handful of manufactures of filter presses, Dorr-Oliver Eimco's AFP IV™ Automated Filter appear to be well positioned to meet these needs. It is design to provide a simple, rugged and reliable solution to the special problems associated with minerals processes. These filters not only provide high throughput and efficient solids capture, but they also operate continuously, automatically, in harsh environments, and can handle abrasive or corrosive slurries. When coupled with simple systems and our operating philosophies, operating costs are maintained at the lowest levels in the industry. The heavy-duty design of our filter presses has been specially adapted for minerals service with several features designed to enhance their performance in such applications.

Highlights include:

  • Up to 15 bar operating pressure
  • Hydra-Shift™ Plate Shifter
  • PLC Control
  • Automatic lubrication
  • Automatic drip trays
  • Automatic shaker
  • Automatic flood washer
  • 10-25 minute cycle times typical
  • Double-ended feed available
  • Available up to 120 Chambers
  • Quick Open/Close Plate Options
  • 1200, 1500, 2000 mm plates
  • polypropylene or cast iron
  • Lower operating costs
  • Recessed plates standard

To review filter press offerings from other manufactures, a good place to visit is InfoMine’s Buyer’s Guide for their list of catalogs.

If you’re interested in learning more about the filtering process, I would recommend you consider enrolling in InfoMine’s EduMine course called “The Mill Operating Resource – 2 Mineral Recovery”