Precious Metal Refining
A Precious Metal is a rare, naturally occurring metallic chemical element of high economic value. Precious Metal Refining is the process of removing any other metals so that the metal you focusing on is more pure or (Finer). Typical bullion grade for minted coins and bars is three nines fine (99..9% fine). At Liberty Refiners we have produced and sold six nines Gold (99.99994 fine). Less than 1 part per million other metal impurities. We typically produce a four nines plus metal purity 99.99 (four nines fine). We will purchase your refined metal or trade you for internationally recognized minted coins or bars.
Mixed Metal Bullion
From Mining Gold, Silver and Base Metals
Bullion from mining operations is typically a mixture of gold, silver and mixed base metals. The percentages of each are typical to a specific mine, Liberty Refiners uses furnasing, wet chemistry and electrochemistry to separate the precious metal from the base metals and bringing the gold and silver to a 99.99 purity.
gold Karat scrap
Here is how karat values break down:
24 Karat = 100% pure gold
22 Karat = 91.7 % gold
18 Karat = 75% gold
14 Karat = 58.3% gold
12 Karat = 50% gold
10 Karat = 41.7% gold
Refining Scrap Metal
Now that we have established that determining purity of a mixed bag of silver jewelry and coins is difficult to do, how do we figure it out? What we do is homogenize the metal and separate it from the non-metal components. The easiest way to do this is to melt it down, all together, with a dose of pure glass to collect the non-metal components. Once the metal is completely molten and the glass has collected the stones and other things, we pour off the glass and take what is called a pin sample. This is done using a glass vacuum tube. You dip the tube in the molten metal which melts the glass. When the seal is broken due to the glass melting, the liquid metal is drawn up the tube quickly and is rapidly cooled. The pin sample is then cut in half. Half is assayed for the silver content and the other half saved in case the assay is challenged. We have a sample as a backup that can be sent out to a third party assayer to resolve the issue.
The assay will tell us the percentage of silver. With this information, because we use electroplating as our primary process to finish our metal, we decide if we have to have to run the material once or twice. If it is below 90% pure it will first have to go into a "roughing" cell. This usually will raise the purity to around 98%. At that point it can be put into a finishing cell.
This process, if done properly, will yield 99.9% pure silver. With our proprietary process we typically get a 99.99% pure product. The silver is then harvested, rinsed, dried, weighed and check for purity. The client then has the option to sell us the silver or get his silver back.