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<br />1 Heap Leach Reclamation <br />' A. Solution Neutralization <br />' Normal working solutions include one million gallons in the ponds <br />and seven million gallons available from total draindown. A cyanide <br />' level of 250 parts per million or 0.5 lbs cyanide/ton water will be <br />maintained. <br />' 8,000,000 gallons x 8.34 lb/gal x 1 ton/2,000 lbs = 33,360 tons <br />water <br />1 0.5 lbs cyanide/ton water x 33,360 tons water = 16,680 lbs <br />cyanide <br />Using hydrogen peroxide at a ratio of 3:1 (from a conversation <br />' with Degussa on average hydrogen peroxide required based on their <br />detoxification experience). <br />' 500 lb drum at 50% hydrogen peroxide strength. <br />3 x 16,686 lbs = 50,058 lbs. hydrogen peroxide needed. <br />50,058 lbs HzOZ x barrel/500 lbs x 1 barrel/50% strength = 200 <br />barrels <br />200 barrels at 5240/barrel = 548,000 <br />' The cyanide will be neutralized through a feeder line of hydrogen <br />peroxide. The hydrogen peroxide will be fed to solutions as they are <br />being pumped from the ponds to the heap for rinsing. The feed line <br />will join the main pipeline just after the pump. Based on literature <br />available on hydrogen peroxide applications, this method is commonly <br />used for application. <br />B. Heao Neutralization <br />During final reclamation the heap wil] be neutralized over a 24 <br />month period. Actual neutralization will occur for 16 of the 24 <br />months with 8 months of winter shutdown. The heap will be neutralized <br />I L-8 (Revised 4/20/89) <br />(Revised 3/14/89) <br />