It is a very difficult and complicated process to refine or recycle gold. Gold refining requires a lot more than just heat from a bunsen burner and a general knowledge of chemistry. Here are three reasons why you cannot perform gold refining techniques on your stove at home and why you should leave gold refining to a refinery.
The crucible is not just a movie or an idea--it is the main piece of equipment in the gold refining process. The crucible is a small cauldron of sorts that can withstand the intense temperatures needed to remove impurities from gold. In it, the refinery places small amounts of impure gold and iron ore. When the two are melted together in the crucible, the iron ore removes all other metals from the gold except silver. (Silver is not drawn to or absorbed by iron ore the way many other metals are, so the silver content remains trapped within the gold that is being recycled.) Even when refining or purifying small amounts of gold, a refinery does not substitute any other type of receptacle for a crucible because of the crucible's well-established abilities to withstand the sustained high temperatures in gold refinement and recycling processes.
The Blast Furnace
This extremely hot oven burns between 1,300 degrees and over 2,000 degrees. When extracting impurities from gold via the use of iron ore, the blast furnace is burning on the hotter end of this temperature spectrum. There is no way for you to reconstruct a blast furnace in your own home or on your own property because of the size of most metallurgical blast furnaces and the amount of pressurized air and sustained, extreme heat needed to produce results.
Two Kinds of Highly Reactive Acid
One of the final steps for gold refining is using nitric acid and hydrochloric acid (the kind that eats holes through soft tissues and other objects) to separate the gold (and whatever silver is present) from the iron ore composites. The highly reactive acids keep these metals separated so that the refinery can harvest the gold flakes, liquid and/or bits from the acid bath. Unless you know your way around acids and safety equipment (which not everybody does) and have an acid-proof tub, it probably would not something you could safely accomplish at home. For that reason and the previously mentioned reasons above, gold recycling and refining processes are best left to the gold refineries who can control each of these steps and provide the equipment, heat, and chemicals needed to purify gold.
For professional gold refining and recycling, contact a company such as Mid-States Recycling & Refining.