The DRYWASHER USES AIR:
Making A Concentrate Using Air:
Here is a picture of a Dry-Washer working.
Why should I use a dry-washer? Well, if we go from a mountain stream to a desert location, we must shift gears. We can use air instead of water to reduce the bank material into a concentrate of black sand and gold. The equipment used to accomplish this is called a dry-washer. There are two types of machines. One uses a bellows to puff air up through a tray. These are sometimes called “puffers”. The other blows air constantly up through a tray. If the air from a constant blower is too strong, it will blow fine gold out of the tray and you will lose it. The puff of air from the bellows, however, will not blow fine gold out of the tray. The bank material must be completely dry for either machine.
he bottom of the tray in either machine is covered with a fine weave fabric that allows air to pass through. On top of the fabric there are riffles going horizontally across from side to side. The tray assembly is used at an angle with the front of the tray lower than the back. The bank material is screened to remove larger rocks prior to entering the tray. The black sand and gold concentrate always collects on the uphill side of the riffles. The brown sand and gravel travels over the riffles and on out of the lower end of the tray. That material is called “tailings”.
I prefer the bellows machine as they are less operator sensitive. The constant flow machines use a 2 cycle gas engine running a blower, and you must set the air flow. The bellows is run by an electric motor or 4 cycle gas engine which is controlled by the speed of the engine, and runs at a much slower rpm. I have taken the tailings from a blower machine and run them through my bellows machine. The result was that my bellows machine removed fine gold from the tailings that had been blown out of the tray by the other machine. However, either machine will work if it is run properly.
You can remove the concentrate from the tray and recover just the gold using a pan. You can be panning like a pro with the 5 easy steps shown in “The Basic Technique Needed for Recreational Gold Prospecting” PANNING – Volume III in “The GREAT AMERICAN SERIES” of e-books on gold.