In our previous article, Refining Gold with Aqua Regia,
we touched upon how to recover gold, or refine gold by first dissolving or converting the gold to gold metal ions with aqua regia. These gold ions or gold chloride move freely through an acidic aqua regia solution and extracting gold is easily accomplished with a little skill and knowledge.
The chemical Bis(2-Butoxyethyl) Ether, also known as Dibutyl Carbitol and Butyl Diglyme, is a clear liquid with a slight odor. When it is mixed with a solution of hydrochloric acid (HCL), or aqua regia, the Butyl Diglyme quickly separates from the other liquids and floats to the top. Butyl Diglyme acts similar to the oil in an oil and vinegar salad dressing. Butyl Diglyme has a very low solubility in water, is easily handled, and is biodegradable. See the Butyl Diglyme MSDS sheet
One of the unique properties of Butyl Diglyme is its ability to recover gold, or gather gold chloride, out of a hydrochloric acid solution such as aqua regia. Butyl Diglyme will reject other precious metals such as platinum and palladium allowing for a complete separation between gold and the platinum group metals. Butyl diglyme is a useful organic solvent used to extract gold from aqua regia and other chlorine based leaches. It is the final separating step in gold purification.
A gold refining process using Butyl Diglyme, is suitable for both large and small gold operations. High cost gold refining equipment is not necessary to extract gold, or refine gold using butyl diglyme. Extracting and separating gold in an inexpensive glass separatory funnel is one option. Gold purification of 99.9% is obtainable from this gold refining, purification process.
Gold processing is fast with Butyl Diglyme because of its ability to extract gold chloride in a matter of minutes, unlike other gold extracting and gold purification techniques which can take hours. The photo to the left shows how to recover gold with the complete separation of gold chloride from the aqua regia, and into the butyl diglyme.
Separation of the newly loaded butyl diglyme from the aqua regia solution, is as simple as draining the aqua regia through the bottom of the Separatory Funnel.
All other precious metals in the aqua regia solution, such as platinum and palladium, remain in the aqua regia and can be recovered using other solvents, resins or selective precipitation.
After the gold loaded butyl diglyme has been separated from the aqua regia, the butyl diglyme solution must be washed with a weak solution of HCL to remove the small amount of contaminants that may have followed the butyl diglyme from the aqua regia solution. A 5% hydrochloric acid solution, or a 1N HCL solution will remove the small amount of iron and other contaminants in the butyl diglyme. The butyl diglyme should be washed three times before extracting the gold from the butyl diglyme to assure a high purity of the final gold product.
To extract gold, or drop the gold out of the butyl diglyme, the butyl diglyme must be heated to approximately 180 degrees Fahrenheit. Do not boil the butyl diglyme solution. Add an equal volume of hot, 10% oxalic acid and keep the combined solution warm for 3 to 4 hours as gold sand drops to the bottom of the flask or beaker. A slow moving spin bar will help speed up the process. After the gold sand has dropped out of the butyl diglyme, recover the gold by filtering the solution through a cloth filter to extract the gold sand or gold mud. Dry the gold mud and smelt it with a little borax to get it back to the shiny metallic gold we all know and love.
Here at Gold River Refining, we do not sell butyl diglyme or any other chemicals. Refining gold should always be performed under a fumed hood with an appropriate scrubber. Do not attempt to refine gold without the appropriate safety equipment and knowing all the risks and dangers involved. Refining gold can be dangerous or deadly if done improperly.