Test Tools Key To Mine Maintenance

Since the early gold fever days in the Alaskan wilderness, finding good tools that can handle the job of mining has been an ongoing challenge. In the hinterlands, mine workers like Chris Kennedy, maintenance superintendent for Teck Cominco’s Pogo Mine, count on the quality of their tools to keep the mine’s complex equipment infrastructure running smoothly.

The facilities at this massive industrial operation operate around the clock blasting, hauling, crushing, extracting and processing ore at a rate of 2,500 tons of raw materials a day. To ensure safety under these challenging work conditions, the site has a rigorous set of rules that govern everything from clothing and lockout/tagout procedures to special permits for confined-entry situations and hot work.

Together Kennedy and his crew of 11 electricians and instrumentation specialists manage and maintain 14 motor control centres and electrical rooms. These facilities contain breakers and the transformers that step 15 kV supplies down to 480 volts to power motors.

Kennedy’s maintenance list includes the powerful blowers that clear diesel exhaust and blast gases from the mine; the equipment that lifts, moves and pulverizes the ore; and 200 pumps of up to 200 horsepower. His maintenance list is extensive and complex, which is why he uses digital multimeters to help streamline this monumental task.

“A multimeter is so versatile because one meter can do a lot of different things when you’re troubleshooting,” he says. “You can use it to look at ohm capacity, at grounding, or at how much current is going through. It pretty much manages the whole gamut of electrical troubleshooting tasks.”

The mine technicians use a variety of digital multimeters, including the Fluke models 87V, 179 and 117, each of which serves specific purposes. For example, since many of the 200 pumps on site use variable speed drives, Kennedy’s technicians use the 87V to filter out high-frequency noise and read the synthetic wave forms generated by the drives. The 179 and 117 are used to verify correct signals from the computerized controls of rock-drilling machines, and to calibrate the density gauges used to measure the thickness of ground rock slurry and water produced in the gold extraction process.

“Gold bearing ore that’s ground up has a specific gravity,” Kennedy explains. “That specific gravity correlates into density. When it’s mixed with water, that gauge reads it. It tells you whether you need to add more water to make it a lighter density so it pumps easier, or decrease the water because it’s too light. The Fluke meter reads the im- pedance at four to 20 milliamps to verify that the gauge is working correctly.”

The Pogo mine, located southeast of Fairbanks, is an underground mine with annual gold production of 350,000 to 450,000 ounces expected over the 10- year life of the project. Teck Cominco has a 40% interest in the mine and is the operator. The other partners are Sumitomo Metal Mining Co. Ltd. (51%) and Sumitomo Corporation of Japan (9%).

While Alaska is known for its beautiful landscapes, it also has an unforgiving climate, especially in winter. “We see temperatures on the average of anywhere from -15C to -23C (5F to -10F) at times,” he says. “The cold causes issues with the variable speed drives. When we hit these freezing temperatures, they just don’t seem to want to work. The electronic boards in there just freeze up.” To prevent these types of problems, the drives are housed in temperature-controlled electrical rooms.

Mining processes bring other challenges. The water used in refining the ore is 100% recycled with zero discharge into the environment. “If you have an upset in the system sometimes your water could be an issue,” Kennedy says. “If it’s too hot and you can’t cool it off fast enough, or it’s dirty, this can cause issues throughout all your other systems that require clean water.”

Distance itself can be a hurdle, since this thriving industrial operation is hundreds of miles away from major centres. This puts a premium on both correct maintenance and product reliability.

As Kennedy explains, things that break can’t be replaced at the store next door — because there is no next door. “It often takes two weeks to get large-size shipments here because they have to come from Seattle by barge to Anchorage, and then get driven up from Anchorage by truck.”

With such logistical challenges to overcome, Kennedy also has a special appreciation for the dependability of his tools. He says that given the conditions, the test tools get more than their fair share of bumps and bruises, but manage to still keep on working. “They’re pretty tough.”

Given the remoteness, the harsh environmental conditions and the wear and tear on the equipment on site, the right tools are paramount to running a successful mining operation. For Kennedy and his team, having rugged test tools in hand makes their jobs a lot easier — and safer.

Colin Plastow has been with Fluke Electronics Canada since 1987 in various support and product management positions. Today, as Industrial Product Manager, he continues to share his knowledge through various customer seminars as well as educational articles. He may be contacted at colin.plastow@fluke.com.

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