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cations for filtering slurries with good fil- terability and for cake washing. Last year, Gaudfrin commissioned a fourth 90-m 2 belt filter at one of Foskor's fertilizer plants in South Africa. The three original units had been in operation in the phosphoric acid plant since 2002, and had proved so successful that when Foskor decided to renovate an older section of the plant, it opted for another Gaudfin filter instead of replacing the existing pan filters there. In another application, Pacific Alumi- nium's Gove alumina refinery in Queens- land uses Gaudfrin filters to remove fine bauxite residue particles from the turbid digestion liquor. Thickeners for the World Market For nearly 30 years, Canada-based Westpro Machinery has been supplying a range of equipment to the mineral-processing industry around the world. Its equipment, including thickeners and clarifiers, is now in use in Bolivia, Peru, Chile, Guyana, Mexico, Russia, Canada, the U.S. and in some parts of Africa. Westpro noted that it supplies its equip- ment manufactured to the highest Canadian standards in components that require little or no on-site assembly. As an example, its high-capacity thickeners are made with diameters of up to 38 m (125 ft), yet the bridges are made to fit fully assembled into sea containers, with the drive, power unit, control panel and handrails all ready to use "from the box." Both hydraulic and electric drive units are available, with benefits including high- torque characteristics, reversibility and vari- able speed capability, the company stated. The units are also light and compact, with low maintenance requirements, it added. The rake assembly features an efficient de- sign that provides higher raking power with less torque, as well as an adjustable slope for on-site customization, while the high-capac- ity tank is generally delivered in formed pieces for field welding, with the individual sections designed to fit into containers. High-efficiency Thickening Phoenix Process Equipment supplies dewa- tering equipment to the aggregate and min- ing industries. For example, its HiFlo thick- ener clarifies the water while it thickens the slurry from a wash plant to 40%-45% solids, greatly reducing the volume going to the slurry pond. For complete elimination of the slurry pond, the company said, a belt fil- ter press can be added to dewater the thick- ened slurry, either initially or as an upgrade. The company claims that separation is often more than 20 times as effective as conventional thickeners. The plant area is greatly reduced, such that indoor installa- tion may become practical. In addition, the design provides for deaeration of the feed ahead of the feedwell, with the feedwell de- signed to enhance the separation. The floc- culation level can be carefully controlled, Phoenix said, with the use of bed-level inter- face sensors for optimum performance. Benefits of this type of equipment include its minimum space requirement and good thickening performance, Phoenix added, with overflow water being clarified for use in the wash plant or as belt wash water for a belt filter press. Using a HiFlo thickener can greatly reduce the volume reporting to a slurry pond, the company stated, or properly condition the slurry for press dewatering to a stackable, solid- phase discharge cake. Other Phoenix products include re- cessed-chamber and membrane filter press- es and piston-membrane pumps which, it noted, can provide alternatives to its core belt filter-press dewatering technology. 52 E&MJ; • MARCH 2014 www.e-mj.com Metso Minerals has designed its inclined-plate settler to minimize the size and cost of gravity-settling equipment. F I LT E R S A N D T H I C K E N E R S EMJ_pg46-58_EMJ_pg46-58 2/28/14 3:11 PM Page 52