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How i built a recirculating sluice box for gold prospecting

Submitted by dredgen on Sun, 04/10/2016 - 22:54

Here is a video of the finished sluice in operation in its final configuration. Read below to highbanker hopper  see how i got here. Here is a video of the sluice being used in a stream in the Bradshaw Mountains of Arizona. I didn't design the sluice to be used in the stream like this, but it works really well.

my first attempt at building a sluice This first attempt was a sort of proof of concept sluice. Just to make sure I could build something that actually separated gold from pay dirt. I didn't put a whole lot of effort (or forethought) into it. I also didn't spend a lot of money on it. I used scrap lumber from around my workshop. I used a 1 x 6 board 36 inches long for the base and 1 x 3's for the sides. The only things I bought for it were 1/4 by 1/4 square dowels to use as riffles. I glued the riffles into it spaced 1 1/2 inches apart. It took only an afternoon to build, and most of that was just waiting for the glue to dry.

my first attempt at building a sluice After the glue was dry, I took it into the back yard and tried it out. I set the bottom of it in a gold pan to catch what washed through, blocked it up at what seemed like a good angle, and placed the garden hose at the top end to provide a flow of water. Then i started slowly pouring pay dirt in the top end. The first tests went quite well. The sluice actually captured most of the gold in the pay dirt. Panning out the material that washed through the sluice only revealed a couple of  gold wash plant small flakes that slipped through. This was very encouraging. However, the mud bog I was making in the back yard with the hose running for long periods, while tinkering with the sluice, was very discouraging. I decided I needed to find a way to capture and reuse the water. So i decided to build a recirculating sluice.

my first attempt at building a sluice I drew up a simple plan for a cradle that would sit on top of a plastic storage bin full of water. The cradle would hold the sluice and allow me to adjust the angle of tilt. Water would be pumped out of the bin to the top of the sluice. Water and debris would fall back into the bin at the bottom of the sluice. This would be great! I'd be able to use the sluice at home without turning the back yard into a mud hole. More importantly though, I'd be able to use it in the field where there was limited water available. I'd designed a recirculating highbanker. I couldn't wait to build it. All I needed was a pump.

The bilge pump used to circulate the water through the sluice About this time I saw an old bilge pump at a yard sale. The guy was asking $5 for it. I talked him down to $3. It looks pretty beat up, but it works great. I glued a PVC fitting on the outlet of the pump so i could attach a hose barb and a smaller hose than the pump was designed for. I went with 1 in. ID hose.

A DC motor to be used as a generator in a wind turbine I built the cradle, again from scrap wood. I had to buy a piece of hose and a few PVC fittings. The spray bar at the top of the sluice is a short piece of PVC pipe with a lot of holes drilled in it. I used a valve to  Dredge factories control the water flow. Again, not much effort, and not enough forethought went into it. I had it done in short order and set it up out back to test.