Filter press operation encompasses the complete sequence of activities involved in running a filter press through its production cycle, from initial feed slurry preparation through to filter cake discharge and readiness for the next cycle. Understanding and optimizing filter press operation is critical to achieving consistent product quality, maximizing throughput, and minimizing operating costs in bauxite, gold, iron ore, and diamond mining plants.
A standard filter press operating cycle consists of several distinct phases. The pressing or plate closing phase involves the hydraulic ram compressing all filter plates together to create a sealed chamber array capable of withstanding the operating feed pressure. The filling or filtration phase involves the slurry feed pump delivering the process slurry into the chambers at a controlled pressure, typically ranging from 6 to 16 bar depending on the application. As the chambers fill and cake builds, the feed flow rate decreases while pressure is maintained.
In membrane press applications, a squeeze phase follows filtration where compressed air or water inflates the diaphragms to mechanically press the cake to its final low-moisture state. A blow phase using compressed air may then be used to purge residual filtrate from the cake and drainage channels. Core blow sequences push air through the feed inlet to clear the central feed channel.
The plate opening and cake discharge phase sees the hydraulic ram retract and the plates shift sequentially, allowing the filter cakes to drop by gravity onto a conveyor or into a chute below. A cloth washing phase using high-pressure water sprays then cleans the filter cloths of residual particles to restore their permeability for the next cycle. Operators must monitor cycle times, pump pressures, filtrate clarity, and cake appearance to identify issues such as cloth blinding, plate misalignment, or slurry bypass.