Coal Age

APR 2017

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20 www.coalage.com April 2017 coal preparation continued duce that to around 0.005 inch with the material that we use." Instead of metal, Schurco's restric- tor components are made of a polymer reinforced with additives such as graph- ite and glass, Pierce said. "You can't bring a static metal component and a rotating metal component that close to each other because if they make con- tact you could have galling," he said. "Be- cause this is a non-metallic material, we can bring those clearances down much further." Other Schurco components, in com- bination with the tight-tolerance lantern restrictor, could reduce water usage. "Spe- cially selected packing that is designed to deform and fill all voids in the annulus of the stuffing box between the bore and the sleeve also plays a critical role in reducing the amount of seal water leaking into the environment," the report stated. Among other things, "the sleeve is different," Pierce said. The sleeve is typically a sacrificial wear part, he said. "We go a step further and do a nickel-chrome-boron flame spray coating on these sleeves that is fusing that coating to the base metal, and then we grind that back to a better- than-a-machine finish," Pierce said. "It The low-flow lantern restrictor, above, is a drop-in package solution that can reportedly cut sealing water usage by as much as 90%. Components include: 1. Shaft sleeve, 2. Gland follow- er, 3. Gland packing 4. Tight-tolerance lantern restrictor, 5. Stuffing box (Photo: Schurco) Six Ways to Optimize Coal Processing by jose marin and eric yan Coal operators need to consider alternative methods to improve ef- ficiency, increase productivity and obtain more from existing mines. Launching new mines may not be an option as the coal industry recov- ers. Here are six considerations from a coal processing angle: Use Suspended Magnets and Metal Detection to Remove Tramp Metal — Properly installed suspended magnets used in combination with metal detection equipment to remove tramp metal will reduce down- time. It has been proven that the combination of suspended magnets and metal detectors outperform the use of magnets alone. The reason is that not all tramp metal is ferrous. Neither a metal detector nor a magnetic separator is 100% effec- tive in removing tramp metal. Double teaming results in as close to a perfect product protection as possible. Working in conjunction, the magnet removes the ferrous materials while the metal detector focus- es on any ferrous missed by the magnet as well as nonferrous metal, i.e. aluminum, copper, brass, etc. Metal detectors provide a solution for detecting medium and larger ferrous and nonferrous particles traveling at speeds up to 1,200 feet per minute (fpm) to detecting small pieces of metal in wet conductive products. They operate by measuring the change in received electro- magnetic signal of material being conveyed through the sensor area. Since the magnetic properties of a material are completely indepen- dent of conductivity, both magnetic and nonmagnetic tramp metals are consistently detected. Install suspended magnetic separators — When addressing the magnetic collection of tramp metal, the suspended electromagnet is undoubtedly the industry workhorse. Collecting tramp metal from conveyed materials, it is a widely used magnetic separator. The elec- tromagnet is mounted or suspended over a conveyor belt to remove relatively large pieces of tramp metal that represent a potential haz- ard to downstream operations. The magnet can also be mounted over feeders or chutes. Continued on p. 22... Suspended magnets used in combination with metal detection systems remove tramp metal and reduce downtime.

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