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Equipment commonly used for small placer operations
By Charles Kubach, Mine-Engineer.Com






Gold Pan - The gold pan is a gravity concentrator, which utilizes the hindered settling and acts like a flowing film concentrator. Gravity concentrating tables, like Deister and Wilfley tables work like a giant gold pan, only much more efficiently. A experienced gold panner can pan one pan of gold in 10 minutes, and in a 10 hour day it is possible to pan up to 1,000 pounds of ore. Results vary dramatically, depending upon the ore and the skill of the user. The shape of the pan makes it work, by swirling the water and allowing lighter particles to go with the water, the heavy ones are separated, and the lights with the water are poured out.

Rocker - The rocker was popular with small placer miners from the early part of the 1900 and is still used today by some hobbyists. It is essentially a sluice that can create it's own "rocking" motion, by manpower. Two people, one on each end, usually, push down on each respective end in sequence, causing the water and material to flow towards the lower end, giving some settling of heavy particles which are trapped by the riffles in the bottom of the rocker. The lighter fractions go out with the water. Rockers require a flow of 5 gallons per minute of water, and on average need 100 gallons per minute for each cubic yard of material. The maximum capacity of a rocker is 3-5 cubic yards of ore processed in a 10 hour period. It does not recover fine gold, though. Rockers are cheap, can be built by an individual from wood and do not require electrical power to operate in remote areas.

Sluice Box - Used widely in the 1800's gold rush days and is still a favorite with small hobby miners today. The sluice box is primarily used for coarse gold recovery, and they require water and ore to operate. As the water and ore flow down the sluice, the riffles trap the heavy particles allowing the lighter particles to go out with the water. The slope of a sluice is important to it's operation and generally should be inch to 1 inch vertical for each foot of horizontal distance. This will keep the water and ore moving at a adequate velocity, not too fast or too slow. These are popular when placers are located in or near streams or rivers, since they require a lot of water. Sluice boxes require 200 gallons per minute of water to operate and generally require between 20,000 and 100,000 gallons per minute of water for each cubic yard of ore processed. Some people will add mats near the end of the sluice box, to help capture some of the fine gold, and they may get 10% to 20% of the fine gold using mats. Mats have been made from almost everything including carpet, burlap, blankets and denim. Sluice Boxes are cheap, can be built by an individual from wood and do not require electrical power to operate in remote areas.

Small dredges - Some use portable dredges, like Keane's little suction dredges to excavate the placer ore from the stream bottoms. These have become popular among the small placer miners in river or stream areas. Generally, these small dredges feed a sluice box.

Centrifugal Concentrators - The newest and perhaps the best innovation in placer equipment has been the development of the centrifugal concentrators, like Knelson and Falcon concentrators. They make small ones 5 inch and 8 inch and 12 inch concentrators which are small enough to transport to sites in a pickup truck,. They require a generator, but they are highly efficient and do well on fine gold.





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