Wharf Resources, a Goldcorp gold-mining operation, is the only operating gold mine in South Dakota and expects to produce as much as 55,000-60,000 ounces of gold in 2013.

Production typically runs smoothly at the above-ground mine site, but when the weather turns to rain or snow, the screen media that they use in the gold-mining process begins to blind over. Screening 500-700 tons per hour of porphyry, an extremely hard rock with large crystals embedded into it, 24 hours a day is challenging, particularly during the winter months. Snow levels have been known to reach more than 4 feet during a single storm, and this can make it nearly impossible to keep up production.During the heavy mud months Wharf Resources would fight with the wet, sticky material to get it to pass through the existing screen media without much success or efficiency. “We get a lot of rain and snow, which creates mud and clay,” explains Dave Austin, crusher maintenance foreman for Wharf Resources. “The mud and clay would blind the screens over. When that happened, we couldn’t get much throughput or screening efficiency.”

General Equipment & Supplies, Inc., Wharf Resources’ local supplier, was familiar with Major Wire and recommended using Flex-Mat® 3 High Performance Screen Media to eliminate the blinding. It took some convincing to get Austin to go with wire screen media, however. “I’m a big believer in polyurethane and rubber screens because of their longevity,” Austin says. “When General Equipment started talking about Major Wire screens, I didn’t listen at first because my experience with wire screen media has been that they wear incredibly fast.”

Wharf Resources installed a new twin-deck screen plant in the tertiary circuit fitted with Major Wire Flex-Mat 3 Tensioned Series S screen media. This new combination made it possible to continue producing in any type of weather, even during the wettest times of the year. “We’ve had no problems with the Major Wire screen media. I was really surprised that they last so long and so was everybody on my team. We didn’t think a wire screen media was capable of lasting as long as these are. It’s amazing when you consider that other locations of the plant using a basic wire screen media are wearing out in just a week,” Austin adds. With the current plant, the Flex-Mat 3 screens are lasting three weeks before having to be changed, saving downtime, man-hours and hassle.

With the aid of the new screening plant and Flex-Mat 3, Wharf Resources has been able to pull the mud out of the existing circuit, thereby reducing the load on the tertiary circuit by 30 percent. “With the new screen plant the entire operation is much more efficient and productive. We started the plant out with Flex-Mat 3 so we aren’t sure how much of the increase we can attribute to the screen media, but we’re happy to say that weather conditions no longer affect production and Flex-Mat 3 has solved our blinding problem,” comments Austin.

Major Wire’s Flex-Mat 3, with its independently vibrating wires and distinctive lime-green polyurethane strips, is available for both tensioned and modular screen decks. It is constructed using polyurethane strips that bond the individual wires together while allowing them to vibrate independently at different frequencies. The increased screening action allows right-sized material to fall through instead of sticking to the wire, virtually eliminating blinding, pegging and clogging.

Flex-Mat 3 is manufactured with abrasion-resistant OptimumWire®, which features a unique combination of ductility, hardness and tensile strength, resulting in the longest lasting wire available. Flex-Mat 3 lasts up to four times longer than traditional woven wire and offers up to a 40 percent increase in material throughput. They provide up to 30 percent more screen capacity than traditional woven wire screen media and minimize downtime spent cleaning or replacing screens.

With more than 125 years in business, Major Wire Industries Limited designs, manufactures and markets screening solutions, including Flex-Mat® 3 High-Performance Screen Media in tensioned and modular versions, OptimumWire® and stainless steel woven wire cloth for the quarry, mining, recycling and industrial markets. For more information or to find a dealer near you, visit www.majorwire.cc or call (450) 659-7681.