Precious metals are treasures as old as time. Their significance has been known for a very long time. As time goes by, the demand for these precious metals keeps increasing, but the supply doesn't tend to keep up with demand. Due to this, new and different methods have been employed to cater to demand.

What is refining?

Refining is the process of purifying an impure metal. It differs from calcining and smelting since in refining, the final material is commonly similar chemically to the original one, only with a purer final product. On the other hand, calcining and smelting involves chemical changes to raw materials.

Why refine precious metals?

You can have total control over your precious metals. Refining precious metals can actually be done at home, thus you can save money while having the overall control on what form you want your precious metal to be in. Most miners do not refine the metal themselves, but it is somewhat common for mining companies to melt down their isolated metals into crude bars which are more pure than the raw metals. Then those crude bars can be sold to a legitimate refinery who will further purify, measure, and smelt into precisely measured bars.

What are the methods of refining precious metals?

1. Low Mixed Content (Sweeps) Refining
   This refers to precious metals with scrap that are mixed with organic or mineral components. These residues cannot undergo the process of melting, thus it requires a special process in order to refine it. The process involves the incineration of residue in a specialized ash producing furnace to eliminate the organic compounds through vapors. After which, the scraps are grinded and screened to separate the metals containing ash particles. It is then followed by homogenizing the precious metals with ash which is used to determine the exact precious metal content.

2. Acid Recovery
   This process involves dissolving precious metals in aqua regalis to extract its content. Through their unique properties, these precious metals are then utilized when separated and recovered from the liquid.

3. Solvent Extraction
   This is the combination of specially made organic solvent which can facilitate extraction in a more efficient and effective method of refining.

4. Chemical Refining
   Chemical refining is used as a refining process which makes use of the old way of separation methods like dissolving, precipitation, filtration and washing. Unlike any other refining method, chemical refining does not involve any representative sample but it involves the use of electrolytes and rinse water to determine the amount of precious metals contained in the scrap.

Precious metals can be considered as the most recycled commodity that ever existed. Their value is unceasingly evident all through nations and generations that every piece of it is important. The processes of refining are centuries old, yet it seems to remain as a secret to many. Recovering precious metals from scraps is of growing importance nowadays because of the increasing demand. It cannot be denied that precious metals will continue to carry high value come what may, thus the process of refining continues to improve as well.