I'm often asked how I process my concentrates and get down to clean gold. The process is fairly straightforward and will help speed up your finish panning while maximizing gold recovery.
Since this article is intended to be brief and to the point, I'm purposely omitting things like "use a safety pan", or "a surfactant needs to be used with gold under 50 mesh", or other 'how-to's'. There are some great videos on panning, so I won't bother discussing panning techniques, just the overall process.
This method is used whether I'm panning my cons or if I'm using a Blue Bowl or Miller Table.
So here we go.
Removing Magnetic Material
I first start by removing as much magnetic material as I can. This process can be either done wet or dry. I prefer to dry out my concentrates and introduce water when I'm classifying. I find it's a much cleaner method and it allows me to start and stop my clean-up process as needed. When removing magnetic material, I recommend the following.
1.) Use three containers large enough to hold your concentrates. Gold pans work well.
2.) Fill the first container with your concentrates. I recommend working in batches. Use a magnet to pull as much magnetic material from the first container and drop it into the second container.
3.) Shake the second container. Use your magnet to pull as much magnetic material from the second container and drop the material into the third container.
4.) Whatever material is left in second container, goes back into the first container.
5.) Then, shake the third container and pull any magnetic material from the third container and drop it into the second container.
6.) Any remainder material in third container goes into the first container. Rinse and repeat 6 times. After the 6th drop, you should only have magnetic material left in one pan.
The reason why we pick up and drop the material is to prevent gold from being sandwiched in-between magnetic material when we are removing it from our concentrates.
Abide by the Gold Rule
The Golden Rule (miner's version), basically states, "if everything is the same size, gold rules". The secret to fine gold recovery is to make all the material size as close to one another as possible. This leverages gold's tremendous density difference.
I'll usually classify my material into 20, 30, 50, 70 & 100 mesh sizes. Most households have a 20 mesh strainer in their cabinets, but to get to the fine material, you will need to classify down well below 20 mesh.
As I mentioned above, I prefer my concentrates to be dry when I'm working with a magnet. I find it's easier to transfer dry concentrates into the classifiers than wet. After I pour in my dry concentrates, I'll then use water to rinse the material through the classifying screens.
After rinsing the top screen (30 mesh), I'll move 2-3 tablespoons of the wet material into my pan. I recommend the Blue Falcon Finishing pan, but most pans will work, provided the pan's surface is smooth and free from deep scratches or gouges. Pro tip: use one pan for the field and one pan for finishing.
After panning my 30 mesh down to clean gold, I'll use a pipette to remove and push aside any other material left in my pan. I'll then use a snifter bottle to suck up clean gold. I'll repeat this process for each classification, but pan in smaller batches to accommodate the smaller material size. For example, if I'm panning 30 mesh material, I'll only pan 2-3 tablespoon at a time. At a 100 mesh, I'll pan one tablespoon at a time.
Out of the River and Into Your Vial
Now the fun part. After panning down to clean gold and sucking it up in a snifter bottle, it's time to transfer in into a vial. First remove the straw from the snifter bottle. Fill your vial with water and begin pouring your gold into your vial by turning your snifter bottle upside down. I recommend doing this over a gold pan or other container. Make sure to thoroughly rinse your snifter bottle to get out any remaining gold.
Take the vial with gold and submerge it in water, making sure to hold it upright. Now, take your vial cap and screw it on under water. This will ensure you don't have any bubbles in your vial.
There it is. That's my recommended process for quick and maximum recovery of fine gold. We offer a gold clean-up bundle that has every thing you need to recover fine gold.