Loading AI tools
Early industrial process From Wikipedia, the free encyclopedia
The Deville process was the first industrial process used to produce alumina from bauxite.
This article needs additional citations for verification. (August 2012) |
The Frenchman Henri Sainte-Claire Deville invented the process in 1859. It is sometimes called the Deville-Pechiney process. It is based on the extraction of alumina with sodium carbonate.
The first stage is the calcination of the bauxite at 1200 °C with sodium carbonate and coke. The alumina is converted in sodium aluminate. Iron oxide remains unchanged and silica forms a polysilicate.
In the second stage sodium hydroxide solution is added, which dissolves the sodium aluminate, leaving the impurities as a solid residue. The amount of sodium hydroxide solution needed depends upon the amount of silica present in the raw material. The solution is filtered off; carbon dioxide is bubbled through the solution, causing aluminium hydroxide to precipitate, leaving a solution of sodium carbonate. The latter can be recovered and reused in the first stage.
The aluminium hydroxide is calcined to produce alumina.
The process was used in France at Salindres until 1923 and in Germany and Great Britain until the outbreak of the Second World War.[1]
It has now been replaced by the Bayer process.
Seamless Wikipedia browsing. On steroids.
Every time you click a link to Wikipedia, Wiktionary or Wikiquote in your browser's search results, it will show the modern Wikiwand interface.
Wikiwand extension is a five stars, simple, with minimum permission required to keep your browsing private, safe and transparent.