In the early gold rush days prospectors used sluice boxes to remove gold from vast amounts of gold ore and gold bearing gravel deposits. The sluice box consisted of a simple wooden trough lined with raised obstructions placed at a ninety- degree angle to the flow of the stream, these are known as riffels.
The water is shut off and the riffels removed, and the heavy materials containing the gold known as concentrates would be gathered. This “run” would sometimes be the gold from several tons of gold bearing gravel. Years ago sluice boxes were built of long wood planks because lumber was cheap and usually easy to get.
The gold bearing gravel was dumped into the upper end of the sluice, the flow of water washed the material down the
length of the trough. The lighter pieces of gravel would be carried in suspension down the entire length of the sluice to come out as tailings at the lower end of the sluice box.
These days sluice boxes are made with materials that are drastically lighter and more durable. Most modern sluice
boxes are made of sheet aluminum or one of the new composite plastic materials.This results in lighter and more
portable units that are considerably more efficient at gathering even the finest of gold dust.
The heavy material such as GOLD, iron sand, silver, lead and sometimes even platinum, sink quickly and are caught by the riffels. Once the riffels gather a goodly amount of the “iron sand” a cleanup would be done.
Portability is the name of the game because most of the gold deposits within easy reach have long since been worked to death. It will be necessary to do a little hiking to be in the best spots for prospecting in the 21st century.
After you have located a promising deposit of gold bearing gravel, walk along the stream bank and look for a
convenient place to set up your sluice box. You should look for a spot where the current is moving swiftly. Once you find
the spot, set your sluice box directly in the current so that the box is filled with water almost to the top of the trough.
To test the current’s ability to carry gravel through the sluice, scoop up a handful of gravel from the creek bed and drop it into the upper end of the trough. If the current washes the lighter gravel down the trough within a matter of seconds, you have found a good location. Brace your sluice box so it doesn’t rock, by the time a couple of shovels of gravel are placed in your sluice should be secure.
Feed your gold bearing gravel into the upper portion of the sluice box in carefully regulated amounts. Do Not overload the riffels! How can you tell if the riffels are overloaded? The top of each riffel should be visible at all times, if you can’t see it then it’s overloaded, you are feeding the gravel too fast. If you overload the riffels the gold will be lost out with the tailings.
Tending the sluice: After dumping each load of gravel into the sluice box check the riffel section for large waste rocks
which may be too big to wash down and are hanging up. Remove them immediately because, large rocks are allowed to rest in the riffel section they will cause the current to wash out all the concentrate from the immediate area of the rock.
If a rock is lodged in the uppermost portion of the trough the washed out concentrate will merely settle in the next few riffels down. But if the wash out occurs at the lower end of the trough the concentrate may flow out of the sluice box altogether! Watch the rocks! Don’t forget to shovel away the tailings from the bottom of the sluice, never allow the tailings to back up into the bottom of the sluice box.
The Cleanup: When the riffels have accumulated black iron sand in amounts extending more than halfway toward the next lower bar it is time to perform a cleanup. Carefully lift the sluice box from the current, keeping it as level as
possible. Carry it over to the bank and set it down on as level a spot as is available. Remove the riffle section of the
sluice, exercising care not to disturb the gravel adhering to it. Roll up the matting which lines the bottom of the sluice
box trough and thoroughly rinse off all the concentrate. This should be done with the matting safely contained in a
DEEP BUCKET so you don’t lose any of the concentrate. Rinse the riffel bars and the trough itself into the bucket, a lot of gold will work it’s way under the matting and may accumulate there.
Pan out your concentrate, do this very carefully since the material in your pan contains all the gold once spread through the several hundred pounds of gravel you have processed through your sluice.