by Gary Pederson, VP of sales for Major Wire Industries Limited- Candiac, Quebec, Canada.
Michigan based Great Lakes Aggregates Inc. produces approximately a million tons of limestone per year at its Sylvania Minerals Quarry located in South Rockwood. As the quarry increased the number of saleable products that it produced, it encountered screening challenges along the way such as limited open area, screen breakage and severe blinding. “With only nine months of production time each year it’s important that we keep production on track,” says Bill Begley, quarry manager at Sylvania Minerals Quarry.
The quarry’s goal was to increase its throughput on all three decks of the wash screens, while producing four different product sizes from clean, high quality minus 3/4-inch material. After several failed attempts with other products to achieve these results, Begley meet with Kevin Hinkley at Conveyall Industrial Supply, Inc. and Brad Rice from Major Wire who recommended they try Major Wire’s Flex-Mat® 3 screen media.
Competitor’s poor screen media hinders production
All three decks of both screen boxes were originally fitted with modular polyurethane panels. The top deck screen had a 1/2-inch opening, the middle deck had a 3/8-inch opening and the bottom deck screen had a .212-inch opening. This system worked fine as long as the load of base materials and washed products were split equally. However, as the quarry increased the amount of washed products, the results were poor quality and lower production rates. The screens needed more open area.
To achieve more open area, the previous screen media provider then suggested changing to their diamond shaped (“D” style) wire openings and supplied urethane bucker bar covers for the flat deck rail bars on the screen boxes to create a crown for the side tensioned panels. These new panels were installed on the top and middle decks of both screen plants. After running for only a few days the screen media panels broke apart causing production to come to a halt.
Flex-Mat 3 quickly makes an impact
Hinkley from Conveyall visited the quarry to take measurements of the screen boxes to ensure everything would fit correctly. Next, they installed Major Wire’s Flex-Mat 3 Tensioned Series D, a diamond shaped media that works well for most standard applications, on both the top and middle decks of one screen box. On their second screen box, for comparison, they installed more of the competitive “D” style screen panels that they had been using previously on the top and middle decks as well.
After just a few days of production, the screen box with the previous screen media on it broke again but the Flex-Mat 3 screen media lasted nearly four more months. Following that, they installed it on the comparison screen and increased production on both screens. “We were really impressed with the wear life of Flex-Mat 3 and excited about the extra production. The other self-cleaning screen media we used didn’t have enough open area and didn’t screen as well as Major Wire’s Flex-Mat 3,” comments Begley. “It has been a good product, very reliable and the price is competitive with other self-cleaning screen media, but Flex-Mat 3 has a longer wear life.”
Flex-Mat 3 Tensioned Series D is now installed on both of Sylvania Minerals’ triple deck wash screen boxes. Production has gone from 39 tons per hour to an impressive 80-85 tons per hour, more than doubling the production of minus 1/2-inch by plus 3/8-inch limestone, which is a premium product used in asphalt. The production of other washed products also increased.
“The durability of Flex-Mat 3 screen media has meant far less time performing maintenance and changing screens, saving valuable operating hours,” says Begley. The plant can now run fewer hours and still put more material on the ground. “The only challenge now is that the tertiary crusher feeding the wash screens can’t feed material fast enough to keep up with the new Flex-Mat 3 screen media.”
Begley wasn’t completely surprised by the performance of Flex-Mat 3 as he had experience with the product while working in one of Great Lake Aggregates’ other quarries a few years earlier. “We were experiencing severe blinding; it was so bad that every 90 minutes the operation would shut down for 20-30 minutes to beat the blinded material out of the screen media with a hammer. The quarry switched to Flex-Mat 3 and never had a problem with blinding again.”
Another challenge faced by Sylvania Minerals was their overflowing settling ponds. Their initial solution was just to build another settling pond but the $100,000 price tag made exploring other options more appealing. In another area of the plant, they installed Major Wire’s HyperSlot screen media. It is a slotted screen media with unique alternating crimped and straight wires. These provide an uneven surface with one straight wire followed by one crimped wire. The crimped wire causes the material to slow down giving the material more time to pass over the openings, resulting in better fines removal.
Since installing HyperSlot screen media on the bottom deck, quarry personnel have noticed a 50 percent decrease in material entering the settling pond, down from the former 220 tons per hour to only 110 tons per hour. The change to HyperSlot screen media has allowed the quarry to delay the creation of an additional settling pond while providing another saleable product. For more product information visit www.majorwire.cc .