Aside from whitening your clothes and making them smell fresh, the use of borax can also be used as a gold amalgamation and smelting agent.
Borax is a non-toxic agent that works well for binding small particles of gold and enhancing the gold smelting process. The borax method of amalgamation/smelting is actually more efficient and a whole lot safer than previous methods used by the old-timers. The borax amalgamation process is currently being used by small-scale gold miners throughout the world, especially in those Third World areas.
The miners’ moss from small-scale mining equipment (sluice box, high-banker, etc.) is placed in a bucket or tub of water containing borax. The borax mixture should have the same appearance as whole milk when it’s poured into a glass, milky white. The miner’s moss or matting is then washed in the bucket or tub just as you would normally do it to free the gold and heavies.
In Third World locales the concentrates are then run through a mini-sluice and reduced and “refined”. The concentrate residue is then placed in a small plastic container and a small amount of water and borax are added. Or, alternately, the concentrates are placed in a gold pan and a bit of water and borax are added to the mix and stirred around.
If you’re using a spiral gold wheel or Blue Bowl concentrator to process your heavy concentrates, make sure you have that add borax to the water until you have that “milky” color. Third World miners then take the final result of their borax amalgamation process, let it dry out, and then place it in a clay or ceramic bowl where they apply a hand-held propane torch to it. Gold melts around 1,948 degrees Fahrenheit, but the addition of borax to concentrates actually lowers the gold melting point down some and helps refine impurities out. The result will leave you with a small button of gold.
This is a great way to deal with that tedious micro-gold in your black sand concentrates.