How Suction Dredges find Placer Gold

Gold Nuggets from a Dredge

With most gold mining operations being small, one to two person jobs, finding the right equipment to match the particular needs of the location is vital to increasing the chances of getting what is needed. This means that the equipment needs to be easy to use and maintain while performing a job on location to bring up the materials that might hold gold flakes or nuggets.

One popular device is a suction dredge that can bring up a considerable amount of material in a short period of time. Suction dredges are relatively simple in construction, easy to operate and allow miners to cover a considerable amount of space in a short period of time. Today, suctions dredges are being used in all parts of the country to find gold and other precious minerals from streambeds, creeks, rivers and lakes.



A suction dredge is a device that is basically a giant vacuum cleaner that sucks up a wide variety of materials underwater, mostly out of streambeds. A suction dredge will bring up rocks, dirt, debris, gravel, silt, and other materials including hopefully flakes or nuggets of gold.

For shallow water, the operator holds the suction hose to the bed of the stream or creek. For deeper waters, a scuba suit is generally needed so that the diver can get close enough to the bottom of the stream in order to suction out the materials that are on the bottom.

Once the hose has suctioned up the materials, they are passed through a recovery system that usually floats on the surface with a sluice box. All the heavier materials which may include gold are trapped in the system while the remainder is washed back into the bed of the stream in the place where it was first removed. In essence, the hole that was created by the suction dredge is quickly filled once the materials have passed through the recovery process.

This means that the suction dredge when properly used causes very little to no environmental impact as the materials are replaced in the same location. This is often misunderstood by the general public, and we are finding that environmental groups are using misinformation about suction dredging as an issue to get it banned and severely restricted throughout many states in the U.S.

Most larger-size suction dredges use a “hookah” air system that is attached to the same power source as the water pump. The air pump is used for the diver so that they can stay underwater as long as the suction dredge is working.



Suction dredges will work anywhere that has water, but they are generally used in good sized streams and rivers where gold is present. When a large area needs to be covered in a relatively short period of time, a suction dredge makes the ideal device to use in these particular situations, more-so than most other placer mining methods.

The suction dredge is an easy to use, relatively simple device that sucks up the materials for hours on end to find potential deposits of gold that lie near the surface of streambeds. It is a device that has enjoyed a great deal of success and will hopefully continue to be used for quite some time in the search for gold.

Next: How Placer Gold is Deposited in Creeks and Rivers

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