Nothing captures the imagination more than an old time prospector mining placer gold out of mountain streams and rivers.  Snow-capped mountains rise up behind him as he works; untouched gold deposits hidden by time and nature.  Back in the 1800’s, all the prospector had was a wooden trough with which to work.  It was heavy and awkward to haul around.  Quite often the miner would build a sluice on location.  However, if he was sampling different spots to any extent, he would start with a gold pan.  He would then do a test production run using a wooden sluice and, finally, build a large, very heavy full production sluice box and start mining in earnest.

Today we’re blessed with modern materials and superior knowledge to create compact, very hardy sluice boxes that can be deployed at a moment’s notice.  Sure, we still use the gold pan to test possible spots …. but just.  Let me explain:

We’re in a medium elevation rock-lined canyon.  The river or stream normally pounds through here pretty good most of the year, but this is late August and there hasn’t been any rain for over a month.  There are some small, very rocky benches now exposed with the low water situation.  Normally these locations would be inaccessible 9/10 of the year.  You work your way down to one particular bench near an outside bend and start panning, and quickly discover that this bench only has about four inches of gravel sitting on top of a bedrock shelf.  Once you start to clear off the surface material, you discover a thin layer of black sand, rich in heavy flake gold and some micro nuggets.

Of course you’re not going to walk away from these riches.  However, there are dozens of now exposed benches through this gorge, all with various mixtures of gold and black sand.  Using your gold pan, it will take you almost a full day to mine this particular rock shelf, and that’s really moving.  But, as good luck would have it (actually good planning), you have a Mountain Prospector sluice box.  Returning to this spot, you accidentally drop your sluice onto the rocks.  Most “tin foil thick boxes” would be badly dented or punctured.  Dents can be pounded out with a rock but this would weaken your box.  Punctures will leak, not to mention seriously weaken the box’s structure.

I’ve built the Mountain Prospector series of sluice boxes to be very tough.  They’re thicker than normal aluminum, and have an advance horizontal classifier system for your fine and flake gold.

This overall design is for toughness and performance.  There are no fiddly parts to screw with, just simple latches and hinged plates.  No lost parts.  The idea behind these sluices is to make them 100% reliable under all conditions and add a high performance fine gold section.

Big gold is easy

Any gold bigger than a grain of rice is very easy to catch.  In fact, it’s hard to lose it.  The last section of these sluices has a more standard riffle system.  This capture area “easily” recovers any gold that makes it by the two dimensional fine gold section.

In the example I was using of the rocky gorge, the larger gold would typically be found where the canyon walls met the rock shelves if there was a slight recess or crack at that point.  Otherwise, an irregular surface on the rock face is needed to anchor the hold particles / nuggets to these benches.

I should just mention opportunities like the rocky gorge happen all the time, but most prospectors miss them because of habit and a head-down mentality.  Don’t be afraid to explore new areas, and definitely seek opportunities for easy gold at low water, rock-lined canyons and submerged sand bars.  Please put your personal safety first in all situations, because dying or getting hurt is no fun.

Two dimensional fine gold section

Looking back in history, the sluice box didn’t change much until the 1980’s.  The 80’s brought us three-stage sluices – three water chutes (troughs) running side by side.  Classification was crude and inaccurate.  A lot of gold was lost, yet it was still better than a single sluice box.  Then, around 2007, a horizontal classifier system was introduced to the gold mining market.  The first couple of years were the learning curve, and then controlling water and materials flow improved a lot.  There are a few manufacturers out there who throw a cheap metal screen into their sluices and claim fine gold miracles will happen.  However:

• There’s no water flow adjstment.
• The cheap screen they use creates too much drag on materials, slowing down the entire process.
• The screen is a fixed height.
• They haven’t allowed for different types of placer deposits – (more black sand, ultrafine gold, etc).
• Their capture media for the fine gold section must have arrived on the short bus, because it likes to jam up if you look at it wrong.

Now that I’ve trashed my so-called “competition” because of bad engineering, I’ll explain how these horizontal classification screens are supposed to work:

You start by feeding roughly classified materials into the sluice box’s crash plate.  Choices on what this plate is made from are:

• Aluminum
• Steel
• Teflon
• Powder-coated aluminum
• UHMW

These materials’ feed areas of the sluice are critically important.  Not only does this plate take the impact of dumped rocks and sand, but also briefly allows the mixed flow of water-laden materials to stabilize before it starts across the fine gold classification plate.  I should also mention that this eighth inch hold plate is flat, which also quickly evens out flow surges and passes a regulated, hydrated fine mixture to the lower gold capture area.

Anything bigger than an eighth inch gets fed off the classification plate and into a large gold capture area.  The beauty of this system is that you can check your recovered gold on the fly.  This is great for spot testing different locations in one area.  I usually dig test holes against a rock wall in a narrow stream valley.  I quite often find “steps” in the adjoining bedrock on the bottom of the valley floor.  This black sand on or near bedrock usually means this deposit was a long time in the making.  Quite often flake gold will occur in thin layers, marking past flood history (flood layers).  If there is only fine gold throughout the magnetite but reasonably coarse gold (micro nuggets and up) on bedrock, this indicates this deposit was agitated from the waterway throughout its life.

Fine gold section

Okay, so once there’s an established eighth inch minus flow of hydrated gold beating materials descending from the classifier plate, it’s just a matter of setting the correct water flow for rapid separation of waste sand vs gold in the capture riffles.  Please remember that we’re separating all of our fines while they’re in / under water on the classifier plate.

By using this method, we’re pretty much assured 99.99% extraction of our fine material.  To begin with, when the classifier plate is in its lowest position, the only water flow is from the top through the classification plate holes.  This would set the water flow rate quite low.  Then, as we raise the plate, water starts to enter from the rear, under the crash plate.

Water intensity grows across the fine gold capture riffles, creating a greater intensity of “pull” of materials that naturally get trapped behind the stepped capture media in the bottom of the box.  So, by varying the plate height, we can change the water pressure in the fine gold riffle section.  Then, when you hit an area with lots of black sand, you just raise the classifier plate for the correct cleaning action of the riffles.  That’s it.

Normal placer deposits just set the plate a little lower.  Curious to what’s going on under the plate?  Just lift it up and have a look.  The pivoting plate also allows you to check your fine gold recovery on the fly.  This also makes it easier to make sure you have the water flow set correctly for the particular deposit you’re working.

I’m constantly using, tweaking and putting more performance enhancements on my sluice boxes.  What you are purchasing is a highly refined, fully functioning production sluice that will make almost all other boxes look like they are from the 1800’s.  You will have fine gold, coarse gold or yellow metal in your box and pocket.  This is a value that will last forever.