Most base metals are removed prior to parting gold and silver. This step is generally done pyrometallurgically, sometimes in the same equipment used for initial melting. In some cases, this step may be performed at the mine rather than at the refinery (for example, on-site retorting for zinc or mercury removal).
Bullion from cupellation is cast into anodes for electrolytic refining. In this process, silver dissolves into a dilute nitric acid electrolyte and plates out on a cathodic surface (stainless steel or graphite) in a very dendritic, crystalline deposit. Gold and principal platinum group metals form slimes which are collected in anode bags. After drying, these slimes are sent to the gold refining area.
Two approaches have evolved for the treatment of gold containing residues. The first is high temperature chlorination of molten metal (Miller process) followed by gold electrowinning in an aqueous chloride solution (Wohlwill process). The second approach is hydrometallurgical involving aqua regia dissolution of granulated metal followed by silver chloride filtration and gold precipitation.
otherwise known as cupellation, is a process in which a precious metal piece is melted down entirely, resulting in the separation of the gold from other metals or impurities. This method allows assayers to physically see what percentage of that piece is pure gold.
Scratch and Acid Test
The Scratch and Acid Test involves scratching the gold piece with a touchstone and then pouring various acid types over it. This process will reveal the karats, or gold purity, of the piece. Though commonly used, the Scratch and Acid Test is quite dangerous and not very accurate.
Gold pieces can be analyzed in a laboratory to determine purity, but such a process requires expensive machinery, lengthy sample preparation, and highly specialized skills by the assayer. Because of this, such a method for assaying may not be efficient for an investor.
Smelting gold is the ability to extract the gold from the ore it is combined with. After smelting the gold is around 90 % pure but not acceptable for the market because it still contains other minerals like silver, copper, aluminum or iron.
Purity & Weight
Most important part of the gold mining process because if done improperly, gold will remain in the ore and profits will be lost. All profits from gold are settled by purity and weight so the more impure your product the less it is worth and the more gold you lose, the less you will net in the end.
Gold Melting Points
Smelting gold is accomplished by using high pressure, heat and various chemicals to breakdown the ore and melt the gold to separate it from the impurities. The gold must be heated to an excess of 1046 degrees Celsius or 2150 degrees Fahrenheit.
Gold & Silver Bullion
Sicottegroup produces a wide range of gold and silver bullion with purities matching the demand from the market. All bars are subjected to accurate and precise inspections and weighing before they are packaged and dispatched.
Unrefined Gold and Silver
Sicottegroup is also an active buyer and seller of bullion and other types of refined Gold & Silver as well as a buyer of unrefined gold and silver. We trade precious metals on global standard prices or against ounces thus catering to small and big clients.
We are capable to supply bullions to our customers as per their needs on a regular basis. We buy un-refined gold from Gold Mining Companies and dealers across globe. We strictly comply with responsible sourcing guidelines.
Accurate: Weighing Your Lot
Once your merchandise is received, Sicottegroup takes great care in the accuracy of weighing your lot. Your precious metals and stones are always under the surveillance of a video security camera to protect your returns.
Gemstone Separation & Frosting
This non-destructive method of stone removal using a metal dissolving process allows for a safe return of your Diamonds, CZ’s, Moissanite and most harder colored stones.
After the gemstone removal process is complete, your stones are carefully cleaned, inspected, weighed and packaged for shipping.