Depending on gold to silver ratio content of the metal, the silver in aqua regia can make it hard to dissolve the gold as the silver chloride forms a crust keeping the acids from dissolving the gold, and then also the gold can make it hard for nitric acid to get at the silver to remove the silver copper from the gold.
See more results
Gold parting is the separating of gold from silver. Gold and silver are often extracted from the same ores and are chemically similar and therefore hard to separate. Over the centuries special means of separation have been invented. The very earliest precious metals had mixes of gold and silver; gold and silver alloy is called electrum.
Parting, in metallurgy, the separation of gold and silver by chemical or electrochemical means. Gold and silver are often extracted together from the same ores or recovered as by products from the extraction of other metals. A solid mixture of the two, known as bullion, or doré, can be parted by boiling in nitric acid.
Older processes explaining how to go about separating silver from gold by cementation were carried on practically in two ways, the first by heating gold for a long time with a mixture which evolved nitric acid on heating, and an absorbent into which any fusible salts ran; the mixture in the second method contained common salt as an essential ingredient, and some material which would assist in ...
Separating fine gold particles from black sands is one of the biggest challenges that gold prospectors have to deal with. This article will describe a simple and inexpensive method of capturing fine gold. Most small scale prospectors do not need to invest thousands of dollars to capture small placer gold dust.
Continue to heat the slag until you can observe the molten gold begin to dissolve away from the rest of the slag. This occurs because of the melting point and the density of the gold as compared with the different melting points and densities of the other metal components of the slag. The gold should slip down into the smelting vessel.
Metallic silver can be dissolved from gold alloys of less than 30 percent gold by boiling with 30 percent strength nitric acid in a process referred to as parting. Boiling with concentrated sulfuric acid to separate silver and gold is called affination. Both these processes are used on a commercial scale for separating silver and gold.