To make gold from a form of chemical extraction known as “extraction by agitation” (also known as the “stirring method” or “stirred precipitating leaching”) involves mixing different substances in a container and stirring them together in order to extract the gold. The process itself is relatively simple, requiring only a few basic supplies and equipment.
The main component of this process is hydrochloric acid, which can be purchased at any hardware or chemical store. It should be diluted with clean, potable water at a ratio of 1 part acid to 3 parts water. This solution is then heated on a stovetop, or in an electric hot plate, and stirred gently until it reaches a temperature of 70°C (158°F). The solution should then be cooled slightly before pouring it over the material that contains the gold (this material is known as the “feedstock”).
The feedstock for this method can be any material containing gold, such as ore concentrates, gold bearing soil, or black sands. It is important to note that the feedstock should be finely ground, as the acid will not be as effective with larger chunks or pieces. Once the feedstock has been added to the solution, it should be stirred vigorously to ensure that everything is evenly mixed. Depending on the type of material being processed, this step may take anywhere from 30 minutes to several hours.
Next, a finely powdered form of aluminum oxide (Al2O3) is added to the solution. This helps neutralize the acid and also serves as a catalyst, helping to increase the rate at which the gold is dissolved. The aluminum oxide should be added in small amounts, as too much can cause the reaction to become too vigorous and cause the gold to be lost in the solution due to over-stirring.
Once the aluminum oxide has been added, the solution should be stirred for another 30 minutes or so to allow the gold to dissolve. After this step is complete, the solution can be filtered through a cloth or filter paper to remove any impurities. The resulting liquid will contain the dissolved gold, which can be recovered by evaporating it to a dry form.
The stirring method of extraction is a relatively simple and inexpensive way to extract gold from ore concentrates or black sands. It does not require any special tools or equipment, and it can be done in a relatively short amount of time. Because of this, it is a popular method of extraction among small-scale gold miners.
