A recirculating sluice box for gold prospecting

One of my many hobbies is recreational gold prospecting. I've been gold panning on my vacations for many years. It's a lot of fun. It's great exercise. I get to do it in really scenic locations. I have even found some gold. However, you aren't likely to find a whole lot of gold by panning alone. To find a lot of gold, you have to pan a lot of dirt. Panning is not a good method for separating the gold from a lot of dirt. It takes too long and is far too much work. There are other methods besides panning to separate gold from dirt though. A sluice is a device that separates gold from dirt and gravel using the power of running water. It will process large amounts of material far more quickly and with less effort than is possible by panning alone. I decided that it was time to step up the amount of gold I recovered on my prospecting outings. I decided I wanted a sluice.

Sometimes there isn't any running water available to power a sluice. A lot of my favorite gold panning streams dry up almost completely during the summer months. So I decided to build a recirculating sluice that would recycle a little water over and over again.

Here is a video of the finished sluice in operation in its final configuration. This sluice went through several revisions and lots of tweaking before getting to this finished product. You can see the entire evolution of this project on my web site. See also my gold panning instructable.

Step 1: Planning the Sluice Box

So what is a sluice box and how does it work? Basically, a sluice box is a long, narrow box with a series of obstructions called riffles in it. If the sluice is placed in a running stream of water, and gold-bearing gravel and dirt is fed into the upstream side, the heavy minerals, including gold, get caught in the eddies created by the riffles, and the bulk of the lighter material gets washed through the box and out the end. Over time, as more and more material is fed through the sluice, more and more gold builds up in it. A sluice box can process much more material, much more quickly than a person, or even a team of people can pan material with gold pans.

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 it in the field where there was limited water available. I'd designed a recirculating sluice or highbanker. I couldn't wait to build it.

The sluice itself is just a simple three-sided box. I decided to keep it simple and cheap, so I made it out if wood. I used a 1 x 6 pine board 36 inches long for the base and 1 x 3's for the sides. It is all held together with Gorilla Glue and screws.  I marked out the location where the riffles would be. I also built and attached a spraybar to spray water into the top of the sluice. More on all this in later steps.

Comments

[afvac]

you make it look so easy to make

[--= Excogitate =--]

Could this be used for diamonds? I have a mine nearby but the water is scarce. I was thinking of a centrifuge powered by a shop vac, but this seems much closer to the techniques already used.

[esemjay]

How do you keep the sand from plugging the pump and the sprayer bar? We've tried nylons over the intake and other screen filters. Best thing for us was placing the pump inside a bucket inside the tub then only pumping the water that overflowed into the bucket. Problem was the pump kept out pacing the overflow.

[brandon borick]

sorry for so many comment put also good job much better than i could ever do i suck at wood working im more of a gunsmith guy my self.

[brandon borick]

forgot to say where in cali right in the middle of gold country.

[brandon borick]

Just a tip this might not work in all cases. Me and my dad are pretty in to this we found that if you use the black pad like you used in the first 1ft and miners moss in the first 6.in on top of the black mat, and just regular box carpet on the rest that we got a bout a 1/8 of an ounce more per cubic yard. We use a 4.in drege when we can and when we cant a 6 ft. long high banker with 4 hp pump.

[TimmyMiller]

where?

[MR JAMES]

cool man just woundering how munch gold you have found and what do you do with it after you find it ? do you melt it down in to gold bar's ? thank's for the project

[rapidprototyping]

many of the desert placers contain gold in a range from fourty mesh to sub micron range. when using a dry shaker you can consentrate these smaller particles but the fines can float off as soon as they are wetted on their surfaces.
Alot dry placers will run .o3 oz per ton and a two inch dredge pump can handle half ton of slurry and pump it to a long tom sluice box. with a tweny fie dollar jump in price of gold to 1250 per oz a lot more people will be trying to get few particles just remember it takes millions of those fourty mesh particles to make and ounce. ande under a two hundred power microscope they look like real nuggets. fun to get them on glass slide and magnify them so you can dream about the gold machine that make you rich.

[szucconi]

Have you thought of building a tray and frame out of something lighter then wood?

[dchall8]

This is very good!  I think most readers will think this is a humorous hobby, but it is very serious.  There is still plenty of gold being mined by hobbiests in California.  Recirculating the water is a great advantage for the dry areas to the south.  Who knows?  There is proabably untapped gold in the dry rivers and streams that only get filled during major storms.  This would allow people access to it. 

[glorybe]

There is no doubt that heavy rains and even a bit of flooding bring gold into streams. People in the hobby look forward to some severe rains now and then as it quickly translates to gold in their collections. And finding ancient stream beds that are no longer streams can be a great source of serious finds as well.