Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr
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48 E&MJ; • MARCH 2014 www.e-mj.com any residual gold from the filter cake before tailings disposal, Micronics reported. Filtering and Thickening Technology Worldwide Part of the Austria-domiciled Andritz group, Andritz Separation offers equipment such as filter presses, belt filters, hyperbaric and vacuum disc filters, and vacuum drum fil- ters for mineral-sector applications. Its range of thickener products includes con- ventional units as well as CCD thickener circuits and flocculation plants. The company reported that for coal- washery applications, its belt presses are used for dewatering fine and ultra-fine coal and tailings, and for recovering process water, while hyperbaric filters find applica- tions in dewatering ultra-fine coal. In- stallations in this sector have included belt presses supplied to the Russian steel pro- ducer, Severstal, and hyperbaric filters to the Czech coal industry for handling flota- tion concentrates. For the iron-ore industry, Andritz Separation has supplied vacuum filter tech- nology mainly to magnetite producers, while hematite operations in the U.S., India and Russia use hyperbaric disc filters. These have more than four-times the throughput of vacuum disc filters, the company said, while reducing the moisture content by an additional 4%-6%. Six 120-m 2 hyperbaric filter units installed at a Jindal Steel plant in India have the highest throughput of any worldwide, the company stated. In non-ferrous mineral processing, Andritz has supplied thickeners for CCD cir- cuits to Nkana in Zambia (six 20-m diame- ter units), Langer Heinrich in Namibia (four at 35-m diameter) and Glencore's Mumi operation in the DRC (six 35-m-diameter). Nchanga in Zambia uses 26, 80-m 2 hori- zontal vacuum belt filters for copper recov- ery, while Mumi has two 122-m 2 units for contaminant removal. Andritz filter presses are in use in various gold and base metals operations in Russia and Kazakhstan, and also for water clarification in underground dewatering plants in a number of gold and platinum mines in South Africa. According to Steve Myers, Andritz Separation's manager for mining and min- erals for North America, recent supply con- tracts won by the company have included six hyperbaric disc filters for iron-ore con- centrate in the U.S. and India, 14 thicken- ers for a major potash plant in Russia and 10 filter presses for a large cement pro- ducer in Germany, as well as 12 cen- trifuges for a Canadian potash plant. Higher-efficiency Feedwell Design U.S.-based WesTech Engineering provides liquid/solids separation solutions for miner- al and industrial applications world-wide. Its product range includes ceramic disc fil- ters, horizontal belt filters, various types of drum filter and tower press filters. In thick- ening technology, it can supply conven- tional as well as high-density and high-flow units to suit specific dewatering and paste production requirements. One of the company's recent technolo- gy developments has been the EvenFlo feedwell. This, WesTech said, induces con- sistent energy dissipation, controlling and equalizing the feed distribution into the thickener, providing enhanced flocculation and optimal mixing. The EvenFlo design consists of a two-part feedwell system, with an inner chamber that converts the feed energy into a concentric radial flow. The main feedwell chamber then evenly dis- tributes the feed into the sedimentation zone of the thickener, minimizing short-cir- cuiting and eliminating uneven coarse- fraction deposits. The EvenFlo is ideal for new thickeners or as an upgrade to existing equipment, WesTech added. In February, WesTech launched its tower press filter to the industrial and min- erals markets. The company said the filter delivers optimum production performance and availability for maximum dewatering in a wide range of industrial and minerals applications, including fine iron-ore con- centrates, leach residues, metallurgical precipitates and more. Other key benefits include low maintenance and operational costs, as well as fully automatic operation. "This technology extends WesTech's abil- ity to directly provide full systems solutions to Top: FLSmidth's Colossal filter press. Below: The company's E-volute feedwell is the result of years of development work. 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 48