Barrick Gold Corp. recently purchased a Wolverine Class dredge from DSC Dredge LLC that will be used at the Pueblo Viejo mine in Sanchez Ramirez Province, Dominican Republic.

Barrick acquired the mining rights to Pueblo Viejo in 2006 and later began a wide-scale cleanup of the area, demolishing existing structures and building new facilities and remediating environmental damage left by previous mining that had ceased in 1999. Barrick’s efforts have included water treatment, restoring the Margajita River’s pH to a level low enough that the waters have returned to their natural color and quality; revegetating 3,500 hectares (8,650 acres) of land to prevent soil erosion; and removing 180,000 m3 (6.35 million ft3) of contaminated soil.

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A 68-ft-long Wolverine Class dredge from DSC Dredge LLC arrives at the Pueblo Viejo mine site (left) where it will be used by mine owner Barrick Gold to maintain a series of sedimentation settling ponds on the property (right).

The dredge was brought in to help maintain sediment ponds built to prevent additional contamination of the local water system. At the site, water that comes into contact with ore stockpiles or waste rock is contained by a series of canals, channels and sediment ponds that hold it until it can be pumped through the facility’s water treatment plant. In addition to contaminated water, silt and sand also wash into these sediment ponds, creating buildup, which reduces their capacity for water storage. Each pond is approximately 150 to 250 m (500–800 ft) wide and 450 m (1,500 ft) long. Dredging allows the silt and sand buildup to be regularly removed from the sediment ponds so the ponds can maintain their depth and prevent overflow into surrounding waterways.

The 68-ft-long (21-m) Wolverine Class dredge is powered by a 440-hp (328-kW) Caterpillar C13 ACERT diesel, can dredge up to 25 ft (8 m) below the surface and offers a 10-in. (25-cm) discharge configuration, which allows particle clearance of up to 6 in. The cutterhead, designed with six cast-steel smooth blades, is attached to a variable-speed, reversible, hydraulic cutter motor manufactured by Kawasaki. The dredge pump, a J30 Metso Minerals/Thomas Simplicity series, is rated for 200 ft (61 m) total discharge head at 4,200 gallons per minute (16,000 l/min). Five hydraulic winches, rated at 4,500-lb (2,000-kg) line pull capacity, are used to swing the dredge, lift the spuds and lift the ladder.