Pit & Quarry, November 2009

S P E C I A L S E C T I O N C R U S H I N G make its concrete backfill The backfill material has a 2 in nominal mix of fly ash and cement designation with an actual gradation specification of 3 in 100 percent 2 in 90 to 100 percent and 4 about 15 percent By sheer size Ames Barrick Goldstrike operation is impressive The gold mine encompasses nearly 10000 acres highlighted by massive equipment not often found in the aggregates industry The volume of material they make and the number of hours they work running double shifts through good weather and bad is a notable feature of the Ames operation The crushing plant is located about 270 miles northeast of Reno and the weather can shift from one extreme to the next The elevation poses a winter challenge in which the second shift in January might experience 18 in of snow 25 º F temperatures and 20 mph winds Summers are dry and temperatures can reach over 100 º F Centerpiece But despite the weather Ames operation runs in high gear driven by the performance of a Nordberg HP400 cone crusher from Metso The first model was used from 1996 2007 producing about 25 million tons of material with little non scheduled maintenance and few breakdowns But in the fall of 2008 the crushers high mileage combined For about 15 years Ames Construction has operated a crushing plant on the Barrick Goldstrike mine property near Carlin Nev about 270 miles northeast of Reno with its reliable performance record led Ames to trade the HP400 for a new one Parts availability is good on that crusher said Ray Deitz territory manager for Metso dealer Compass Equipment Inc Compass is based in Oroville Calif but has serviced Nevada full time for the past three years The first crusher they got in there for a test run lasted 10 years and did all of those millions of tons Its just a tough crusher Barrick provides the tunnel excavation and overburden materials to Ames crushing plant stockpile for processing Since the excavation and mining activity is at different elevations and different seams the geology will change from hard granite to limestone Ames new crusher is capable of 400 500 tph with average annual production of 2 million tons over 4000 hours depending on the weather and feed material gradations In one year bridging the 2008 09 spring seasons the crusher produced a record 29 million tons of material It is the whole operation Its a great piece of machinery and without that we couldnt get the job done said Mike Shields Ames crushing supervisor of the HP400 We like the durability of it the ease of sizing the cone and its just really easy to maintain Its pretty much exact compared to the original model except for the great strides that were made on the lube system Added Deitz The lube package is a lot more operator friendly The old unit would sit up with the crusher and take a pretty good beating Now the tank the tramp system and the hydraulics are all together in one cabinet It sits off by itself on the ground and saves the operator a lot of headaches Ames original HP400 cone crusher above saw 25 million tons in 11 years and was traded for a new one in 2008 20 PIT QUARRY November 2009 www pitandquarry com