Aggregates Manager Digital Magazine
Issue link: http://read.dmtmag.com/i/932759
EQUIPMENT MANAGEMENT 30 AGGREGATES MANAGER / February 2018 O ver the past several years, the popularity of the fi lter press has increased dra- matically, making it one of the more popular methods to process and dewater tailings. Other outside factors are also pushing producers to invest in a fi lter press. Due to changes in regulation and permitting processes, it has become increasingly hard to obtain permits for settling ponds. Having enough space at a site can also be an issue. Settling ponds may not fi t expansion plans because they prevent access to and use of saleable product. Additionally, equipment such as belt presses often produce a moister cake using chemicals, while fi lter presses can achieve the needed drier product and require no chemicals. How does a fi lter press work? At its most basic level, the fi ltration cycle of a fi lter press consists of covering re- cessed plates with fi lter media, applying enough force to create a seal between the fi lter plates perimeter surfaces, and then using a feed pump to supply the pressure necessary to pump the slurry into the cavities formed between the sealed plates. The fi lter cloth captures the slurry solids between the fi lter plates while allowing the fi ltrate water to pass through the cloth mesh and exit through ports in the fi lter plates. When the chamber becomes completely full, the feed pump stops and the pressure that seals the plates is released. The plates are separated allowing the dry cakes to emerge from the chamber and fall to the ground below. Most people think that the fi lter plates squeeze together to expel water, but the press never moves during the time of dewatering. The only movement by the press is when they are opened and closed to expel the dry cake or to begin a new process. Plates simply con- nect to form a seal; the feed pump sup- plies the necessary pressure to dewater the fi ne solids. Filter presses were designed for simple and limited movement. This de- sign leads to high-levels of automation An increasingly popular choice for dewatering, fi lter presses can save space and allow for additional mining, but must be cared for properly. When the filter press chamber becomes full, the feed pump stops, and the pressure that seals the plates is released, allowing the cakes to fall to the product pile below. Keep Your Filter Press Fit