A mobile batch plant produces concrete that will never see the light of day.
It’s a long way from Texas to the Athabasca Oil Sands in eastern Alberta, Canada. But the San Antonio-based underground concrete backfill and shotcrete firm, Mining Concrete Ltd., has been hired to place concrete in the ultimate remote location: an abandoned mine.
Mining Concrete, a division of Robert Ober & Associates, and sister company of Plant Architects and Plant Outfitters, is undertaking a major project at Suncor Energy’s Fort McMurray oil sands operations near the McKay River. Known as the Dover Mine Site, the project involves extracting specialized underground equipment for reassembly and display in the Oil Sands Discovery Centre in Fort McMurray.
In November 2012, Mining Concrete set up a Liebherr Easymix 1.0 mobile plant with a 1.3-cubic-yard pan mixer, and got to work. First the mine, which had been abandoned for several years, required environmental and safety assessments and a new main hoist wire rope. Then the team completely thawed the mineshafts and mine drifts, and built underground concrete dams and coffers to contain the ice melt. Due to extreme temperatures, as cold as -60 degrees F on the surface and in the mine shafts, they have produced both slow setting (with high fly ash content) and self-consolidating concrete mixes.
Mining Concrete is now fabricating huge underground steel bulkheads with concrete foundations and completely filling in both mine shafts with concrete. The concrete is pumped through a series of insulated pipelines and delivered several hundred feet below the surface.
In addition to the concrete placement, a team of ironworkers, millwrights, electricians, and a specialized group of underground rock miners from Mining Concrete’s Ontario division are working on an accelerated schedule to complete the project by July 2013.