One method of separating gold from other metals, something commonly done with household electronics, involves using a tilting furnace to create a liquid metal mixture known as "slag." This slag is then heated, and the gold separates from other metals by dissolving away from it.Continue Reading
You need a tilting furnace, a silica, a gold-plated circuit and sodium borate for this method. It is also important to wear suitable protective gear, such as overalls, gloves and goggles.
Place the circuit inside the furnace, and begin heating the furnace. Wait until the heat inside the furnace reaches a temperature of around 1200 degrees Celsius.
On top of the gold-plated circuit, mix the silica and sodium borate chemicals into the furnace to create the slag. Make sure you look at your furnace's usage instructions to do this correctly.
It takes more than an hour for the metals to dissolve and the slag to develop. If the metals have not dissolved after about an hour and a half, raise the temperature of the furnace by about 200 degrees Celsius.
After the slag has been heated for long enough, the molten gold begins to dissolve away. Allow the gold to slip down into the smelting vessel. After this has occurred, wait for the gold to cool, remove it from the smelting vessel and remove the slag.