Aggregates Manager Digital Magazine
Issue link: http://read.dmtmag.com/i/883641
AGGREGATES MANAGER / October 2017 23 EQUIPMENT MANAGEMENT beginning to drill, because if you can't hold that hole open, you are in trouble. 5) Use a larger-diameter drill string. Compared to the diameter of the bit, a comparatively large diameter drill string is stiffer and minimizes hole deviation while it maximizes air-flushing capac- ity. This is especially important when drilling in porous material that bleeds off the air. In using a larger diameter pipe or drill rod, check to ensure ade- quate clearance is being maintained for cuttings to flow to the surface. With that provision met, the velocity of the flushing airstream is increased or bet- ter maintained, which, Hissem observes, helps the operator maintain a hole-to- hole cycle time. 6) Develop a sixth sense. Watching only gauges can be self-de- feating, because, by the time they regis- ter an anomaly, something significant already has happened in the ground. Hissem talks of the old days when drill operators were exposed to the heat and cold and dust and noise. "Then we got cabs and old-timers didn't like it, even though they were more comfortable, because it cut them off from sensory in- formation." So-called "smart drills" are being developed with onboard intelli- gence and systems that will separate operators even more from the "feel" of operation. Until such machines dominate drill sites, operators should keep sens- ing the pulse of their machines. They should actively monitor such things as the flushing action, any pitch changes in the drill string, subtle movements that indicate a change in rock pressure, the size of cuttings, and groundwater. Hissem believes a master driller can fully develop this "sixth sense" in a couple of years. Bonus tip for management: Be careful how you motivate operators. Quality control should vie with produc- tivity in determining the success of an operation. If the only directive to those in the field is to get it done fast, oper- ators will take costly shortcuts to gain footage per hour and please the boss. But holes will angle off, safety will be compromised, and, ultimately, more ex- pense will be incurred. Hissem recalls the advice of his grandparents to "make haste slowly." Or, to use another maxim, look before you leap. "Rarely can one rush quality," he says. AM Get your damaged SBR conveyor back in service in just 90 minutes! Heavyweight SBR conveyors are the major arteries of mining and aggregate processing operations. Left unrepaired, a small gouge, tear, or problem with a cold vulcanized splice in a belt could shut down an entire plant . R-Flex ® Belt Repair Kit Devcon ® R-Flex ® Kits contain everything you need to repair a damaged SBR conveyor belt and return it to service... in just 90 minutes! And R-Flex's enhanced formulation offers increased flexibility, improved crack resistance, and longer working times in hot climates. An ITW Polymers Adhesives Brand For more information visit: www.devcon.com/RF or call Devcon Tech Service: 1-800-933-8266 17-066 R-Flex Island-half (AgrtMngr).indd 1 3/21/17 10:31 AM Untitled-10 1 8/2/17 2:33 PM Article is courtesy of Sandvik Mining and Rock Technology.