Refining removes from smelted gold impurities such as traces of other unwanted minerals and metals. Refining can be achieved by processing the gold in a chemical bath, or by using a safer, salt water solution to refine the gold.
A salt water based refining machine requires several components to fully function. A standard home kit will require a drum and lid, saltwater solution, and catalyst powder. The machine runs off a DC current, and some require a rechargeable battery pack.
The gold is placed in the salt water filled drum, which separates and dissolves the gold from the other metals. An internal ceramic plate stops the gold from plating. Catalyst powder is added to the solution and transforms the pure gold, but none of the other metals, back into solid form.
Salt water refining is an economical way for small business to refine gold. It does not require the harsh chemicals, such as nitric or hydrochloric acid, which are used in a standard refining process.