Processing, smelting and refining gold World Gold Council
The Miller process is rapid and simple, but it produces gold of only about 99.5 percent purity. The Wohlwill process increases purity to about 99.99 percent by electrolysis. In this process, a casting of impure gold is lowered into an electrolyte solution of hydrochloric acid and gold chloride.
In most cases, the gold is 99.9 percent pure. Workers cast the gold produced during refining into bars. What happens next depends on how the gold will be used. Pure gold is generally too soft for most practical applications, so other metals are nearly always added to it. When gold is combined in this way, it forms an alloy. Scientists and goldsmiths often use colors to designate the various gold alloys that
Gold processing, preparation of the ore for use in various products. For thousands of years the word gold has connoted something of beauty or value. These images are derived from two properties of gold , its colour and its chemical stability.
The gold refinery can sell the gold to other companies like recycled metal suppliers, jewelers, and electronics manufacturers. The processes at a gold refinery can vary. Processing precious metals requires the use of caustic and toxic chemicals, and historically pollution was a problem with many refineries. Some companies pride themselves on environmentally friendly practices and may
How to Refine Gold. You may want to make some extra money by refining your own gold at home, or you may be a jeweler who wants to refine gold inhouse. There are multiple ways to refine gold on a small scale as
Gold is processed by cyanide milling, a chemical procedure that separates 95 to 98 percent of the gold from raw mined ore. It is then refined to the gold standard purity, according to Mineweb. Heap leaching is a less expensive method of gold extraction, but it is a longer process and it recovers less gold than the cyanide milling process.
Gold Refining Process. The gold occurring in the alluvium is not refined by any of Natures processesbut the accompanying minerals or metals are either oxidised or removed hence, in the recovery of gold from reefs impurities are often collected and introduced, thus making it of lower value than the corresponding alluvial gold,...