You have taken the plunge and sent your gold and other precious metal which is surplus to your requirements in to a gold buyer and you have received your check but, aren’t you interested in what happens to your old pieces and scrap precious metals now?
The scrap precious metal which is bought in from the public will now go through a refining process which will involve the metal being sorted, weighed and analyzed. This process involves checking and rechecking the metal at every step of the refining process, in a meticulous and documented fashion, because this is a necessary part of the requirement to satisfy numerous regulations on purity control and for applying hallmarks.
Smelting
Once logged in and checked, the scrap precious metal is transferred to the smelting department. Smelting is the process by which the metal is heated and infused with a special additive, known as a flux, and the metal is melted. The flux allows for the metal to melt more easily and for the pure metal to be mixed thoroughly providing uniform purity level.
Once melted, the metal is poured into a mold and allowed to cool until solid again – this forms bullion bars which are then sampled and weighed.
Assaying
Assaying is the process by which the bullion bars are analyzed to determine the level of precious metal in the bullion bars. Obviously, greater levels of precious metal make the bullion bars more valuable. The analysis takes the form of two samples taken from each end of the bullion bar and these are put through a “fire assay” test – it is this test which provides the level of purity of the bullion bar.
Gold Refining: The Miller Process
At this point we have bullion bars which are not pure gold, platinum or whatever precious metal is involved – we have an alloy or amalgam with a mixture of precious and non precious metal content. The bullion is now melted again for further processing so that the separate metals can be extracted and when producing “fine gold”, the Miller Process is used.
After the bullion bars are melted, chlorine gas is then introduced into the molten mixture which reacts with silver and non precious metals to form solid compounds (known as “chlorides”). These float to the top of the melt and are skimmed off for further refining to extract the silver. What is left is at least 98 gold and must now be further processed using electrolysis.
The result of electrolysing the gold melt is to produce pure, 24k gold and a solution which contains platinum and palladium which is in turn extracted at a later stage.
This whole process generates only a quarter of the pollutants and waste products which traditional smelting operations generate, and a tiny fraction of the adverse environmental impact that mining the gold from the ground creates.
Platinum Refining
Platinum is an extremely valuable precious metal, more valuable than gold at the moment but it also produces a large quantity of waste and extremely toxic pollutants. The “Column Process” greatly reduces the pollution and toxins which traditional platinum and palladium refining generates. The metal mix is placed inside a column with an acid solution which digests the precious metal, but because it is self contained, there is no excessive use of toxic acids and the creation of waste is minimized.
![[Valid RSS feed]](http://www.look4articles.com/images/icon_Rss.png "XML Feed For RSS"){kind=icon}
Category Rss Feed
Print This Article
Add To Favorites
![[Valid RSS feed]](http://www.look4articles.com/images/rss.jpg "XML Feed For RSS")