Gold Extraction Techniques - Manhattan Gold Silver
When the Lydian Empire was standardizing the purity of the gold and silver they were using for the world’s earliest coinage, this was the method they relied on. When mined, gold is commonly merged with silver as an alloy called electrum. Although primitive, salt cementation could separate the two elements and yield gold exceeding 90% purity.
Smelting and Roasting Ores to recover gold, silver and other.
For small scale treatment by individuals, the method is to grind the ore up finely, put it in some sort of tub and keep it moist. Stir and turn it over from time to time to allow the air access to the material. Natural bacteria found in sulfide ore will do the rest.
How to Separate Precious Metal | DoItYourself.com
The gold should slip down into the smelting vessel. After this occurs, you can cool and remove the gold from the smelting vessel and also remove the slag as well. It's common at this point to refine the gold through a separate refinement process to ensure a high level of purity. For more information on refinement procedures of this type.
PARTING: Separate Gold and Silver by Melting
The gold thus obtained is usually of a fineness of about 997 or 998, the remainder being chiefly silver, which would not pay for extraction although part of it could be separated with a further expenditure of time, fuel, and acid. The gold is pressed by a hydraulic ram, the pressure exerted being about 800 lbs. to the square inch.
Hard Rock Mining Gold and Silver Ore and processing it
The gold and silver bearing liquid, called pregnant solution, is separated from the ore by various drainage and filtration processes. The most common methods to remove the gold and silver involve activated carbon, or zinc precipitation. The carbon method requires an additional step where the metals are removed from the carbon.
Gold Smelting Refining Process - 911 Metallurgist
Silver-gold concentrates can be smelted too. Under this consideration, a concentrate must contain at least 20 oz/t of gold. Obviously, if the higher grades are better and 50 oz/t is a good average value. It is important to mention that a silver-gold concentrate obtained by flotation has a high silver content.
Cupellation - Wikipedia
To separate the silver, the alloy is melted again at the high temperature of 960°C to 1000°C in an oxidizing environment. The lead oxidises to lead monoxide, then known as litharge, which captures the oxygen from the other metals present. The liquid lead oxide is removed or absorbed by capillary action into the hearth linings.