Technologies in Alluvial
Auriferous Mining

Hydraulic disintegration. Usage of monitors
Hydraulic dredgers use water to transport the dredged material. The material is picked up by the suction of a pump, and then transported through a pipeline in the form of a slurry. A technique of disintegrating rock at rates appropriate for fast excavation is looked into. The technique makes use of a high speed water slug to produce strong elastic water hammer kind of pressure pulsation at the moment of contact between the water and the rock. Test slugs that are up to one half pound weight with a velocity of up to 800 ft/sec are aimed at a target. The nature of the slug at impact is checked with rapid speed photographs and the nature of the outgoing pressure pulse is measured with a quartz transducer that has been placed in a metal target. Tests up to now demonstrated developed pressures of a functional scale and extent of time. The scale approximates what is caused by a plain water hammer. Planned tests on a number of rock samples will weigh up the reaction and erosive losses of the rock for certain slug firings.

This requires a body of four to five meters or more in different levels and the source of a strong hydraulic source for the usage of high pressure pumps, its nozzle is variable in relation to the cut or jet of disaggregated transport. For more efficiency of movement of the top layer of the earth, it is suggested to produce the impact of the jet on the base of the body, mainly in sandy layers that easily undermine and that cause instability in the talus, which causes the tumbling down of the floor structure to disintegrate. The method of monitoring that follows is carried out in auriferous mining placers such as benches and alluvial terraces and is a very economic, clean and efficient method. On the bank of a river, its performance stand out in a big way three times that of equipment of earth movement, weighed with the cost of investment one to ten of a bulldozer.

A monitor of six inches with a pump of 6 inches x 36 C.V. per day displaces 1,000 m3. When the areas that are to be unloaded are in 200 meters on the shore of the river, it is enough to eliminate the disintegrated floor or well drain with a pendent of 0.5 percent, at greater distances the elimination of overburden is done with another unit of pumping of solids that releases at any natural depression on the mountain terrain. The implantation of this type of work is very important in auriferous mining, especially in places where labour is scarce and has a high cost; its usage allows the movement of earth of three shifts in twenty four hours.