Black sand concentrates are a combination of minerals in the iron group: Hematite, Fe3o3, with a specific gravity of 5.26, an iron mineral that is non-magnetic and Magnetite, Fe3o4, with a specific gravity of 5.20, is magnetic. These black sands will weigh a third (1/3) to a fourth (1/4) the weight of gold (Au). Gold has a specific gravity of 15 to 19.3. A cubic foot of wet black sand will weigh 225+ pounds or 26.7 pounds per gallon. These heavy concentrates present the major problem in the gold recovery process for the average recreational gold prospector. Gold with a specific gravity of 15 to 19.3 and black sand at 5 to 6, when classified to the same mesh size, will allow the gold contained to be easily recovered. Without classification, gravel three times the size of gold will be recovered with the gold, hence the necessity for proper classification.
Try one of our black sand magnets for quick and easy gold panning cleanup.And practice your clean up with one of our gold panning bags loaded with real gold.
Just for fun: Picture above shows California Black Sand under a microscope. Visit the following link to see more close up shots of various sands from around the world - pretty interesting.
What other prospecting tools are there to clean up black sands?
Besides the inexpensive gold magnet (see below) you can move up to a mechanical gold wheel or blue bowl.
We need your black sands for testing new equipment! Sell us your black sand concentrates (with or without gold). Email info@goldfeverprospecting.com with how many pounds you have available.
Spiral Gold Wheels
Peter Callinicos, Copyright ©, 1997
Why Use A Gold Wheel?
How many of you have attended a gold show and watched with fascination as gravel is fed into a spiral gold wheel and the gold appears along the spirals then disappears into the center hole and lands in a cup?
For those of us who process lots of black sand the choices on how to process the sand is limited to panning, using a "Micro Sluice" or a spiral gold wheel.
After panning for many years I always ended up with back sand in the gold...ALWAYS! The micro sluices work OK but are slow and I still end up with black sand with the gold. However when properly set-up and run, a spiral gold wheel will process 50 pounds of concentrate an hour and give you perfectly clean gold!
So if you run lots of concentrate, do not want to sit for hours on end (no pun intended) the spiral gold wheels are worth consideration.
Operation
Many years ago Gary Christopher, owner of Prospectors Cache Prospecting Store and a spiral gold wheel manufacturer, was asked if his gold wheel was any good. His answer then is as valid today was, "The wheel is only as good as the operator!" If you do not understand the operational theory of gravity separation, and understand the importance of classification of the gravel to be run into a 3 to 1 ratio then the results will probably be poor.
For best recovery your gold recovery machine should have a green or blue wheel. You should use Jet Dry®, at the rate of three drops per five gallons of water to prevent gold from floating out of the wheel. The tilt of the wheel should be 45 degrees to start, water flow adjusted to an even flow without splash and the black sand pyramid adjusted to an inch below center hole. Use wheel tilt to adjust pyramid, not water flow. Once the water flow is properly set, no further adjustment is required. Check gold cup for black sand and re-adjust wheel if necessary. It is possible to recover over 90% of the gold in your concentrate if your wheel is properly set-up and your concentrate is properly screened.
The new age of computer designed gold wheels with built in agitators are well worth consideration. The new agitator wheel, turquoise in color, will fit most all older 13" gold wheels and pay for itself in short order. Also available is a micro adjuster for the older 13" gold wheels that allow micrometer like adjustment for near perfect gold recovery.
The Blue Bowl
Of all the black sand separation methods, the Blue Bowl will probably save the finest gold without resorting to mercury or other chemicals. It used to be called the D.A.M. Bowl but Pioneer Mining in Auburn, CA aquired the patents and the molds and now it's just called the Blue Bowl (I can't imagine why). They work best with materal that will go through a 30 mesh screen but I have had pretty good luck with material between 20 and 30 mesh. Any of the black sand separators mentioned on this site or a gold pan will work OK for material over 30 mesh. You can buy just the bowl or in a couple kits one of which has virtually everything you need.
If you bought one years ago, the instructions weren't all that great. Much improved instructions are available on Pioneer Mining's web site.
Some info courtesy of miningold.com
We need your black sands for testing new equipment! Sell us your black sand concentrates (with or without gold). Email info@goldfeverprospecting.com with how many pounds you have available.
