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Gold/Mining/Energy : Gold Price Monitor -- Ignore unavailable to you. Want to Upgrade?

To: loantech who wrote (89218)	9/2/2002 7:56:15 PM
From: E. Charters	Respond to of 116912

A giant was a pressure fed water nozzle for use in the placer mines of California. The 19th century technology was perfected there, in placers like the Ross Valley. They also perfected the airlift pump, which was a suction dredge that used a pump that directed a flow of water up into a pipe from the nozzle creating suction. You could lift materials any height, weighing several hundred pounds. One such pump was used to move hundreds of tons per hour of boulders. They also built water pressure operated cranes, that lifted large boulders of up to 100 tons. The giant operated on pressures of up to 125 pounds of water per square inch, with flows of thousands of gallons per minute. A typical giant could direct a stream of water aerially 1/4 of a mile and at that distance its impact could kill a horse. The Ross placer used several of these giants to move several thousand yards of gravel per hour into several sluiceways carved into the valley and dammed with wooden and rock sides. The main sluice itself would be one mile in length, perhaps 25 feet wide and 12 feet deep in water. The riffles were 4x4 and 8X8 inch posts some 4 to 6 feet in height driven vertically into the soil. The water in the sluice coursed at about 25 miles per hour, and if a horse or man fell into the sluice they would drown. It was found that most of the values reported to the first 1/4 mile and most of those values to the first 100 yards, with perhaps 10 to 15% in the rest of the sluice. Mercury of about 1 to 2 pounds a day was poured into the sluice to collect the gold. It is said that 95% or so of the mercury was recovered on clean up. Once every 3 months or so, the flow was stopped and the sluice cleaned. Armies of men called snipers would descend with pans and rockers to remove riffle posts and pan the concentrate to bedrock. The riffles were sawn on the ends which looked like a broom, and the ends burnt and panned. The largest problem facing the placer miner operating a sluice was availability of water, which was sold to miners by a system of measurement called miner's inches. This was the water that would flow over through a dam opening onec foot wide, an inch high at one foot depth. At the Ross place in California, there were 5000 miles of wooden and iron pipeline supplying water, which was ditched from 30 miles away. EC<:-}