Pit & Quarry, June 2014
UNsettling A California quarry gets its settling pond problems settled once and for all F or decades workers at Stevens Creek Quarry in Cupertino Calif dreaded the monthly need to drain and clean out the quarrys settling pond for its excess slurry tailings Every 30 to 45 days the entire operation had to shut down for up to eight days while the pond was cleaned costing up to 80000 each time Owner Rich Voss and his son Operations Manager Jason Voss were frustrated by the lost time high costs and mounting inconveniences associated with the settling pond Natural raw materials never consolidated in the pond so flocculent had to be mixed into the tailings to allow settling making disposal possible at the reclamation site Once the tailings accumulated in the pond the plant had to be shut down for the pond to be cleaned out and made operational again Additionally WASHING CLASSIFYING the 170 acre operation had limited space for creating a second settling pond that would allow work to continue uninterrupted It was such a problem being down for seven or eight days while the pond was being maintained Jason Voss says That and the costs of it made it a real issue for us It was an issue that wasnt going away if we didnt find a solution Fines recovery Rich Voss called Scott OBrien director of process engineering for McLanahan Corp and Ron DeDiemar an industry consultant OBrien and DeDiemar took samples to be analyzed for potential options to de water the fines from the effluent and help Stevens Creek eliminate the need for a settling pond altogether After analyzing size gradations in the materials to determine the amount of easily recoverable sand an Ultra Fines Recovery System was BY ANDREA R ITCHEY 12 PIT QUARRY June 2014 www pitandquarry com
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