was not employed for use, but was an approach that was explored. Louis Le Chatelier, in 1855, created a process that produced aluminium hydroxide by heating in sodium carbonate and then leaching. Bubbling through the solution with carbon dioxide precipitated aluminium hydroxide, which when dried, allowed for the recovery of alumina. Bayer's contribution to aluminium ore processing Bayer worked in the textile industry in Saint Petersburg, where aluminium hydroxide was used to help affix dye to the cotton. While working he made two important discoveries regarding processing steps that helped separate the Bayer process from that of Le Chatelier. In 1887, Bayer found that by using a pure seed of aluminium hydroxide, a crystalline precipitate formed that was more economical than that obtained by Le Chatelier. He later patented his discovery in Germany, the United States, and the United Kingdom in 1887. In 1892, Bayer discovered that by using an autoclave, or a pressure leaching vessel, in combination with a sodium hydroxide leachant the process resulted in a very pure sodium aluminate solution that could be used for his precipitation step that he discovered previously. Both steps are widely used today but have been improved upon as technology has evolved. After discovery, Bayer worked as a startup consultant for alumina manufacturing around Europe. Bayer returned to Austria in 1894 to start an alumina factory but was unable to secure enough capital to fully fund the project. Importance to the aluminium industry Alumina and aluminium production underwent significant changes in processing due to discoveries made by Karl Bayer, Charles Martin Hall, and Paul Héroult. Hall and Heroult share credit for inventing aluminium electrolysis. The Hall–Heroult method is the primary method of producing modern aluminium and requires high purity alumina to produce aluminium. The Bayer process produces high purity alumina which is then used in the Hall–Heroult process as the main raw material. In 1900, aluminium was valued at the equivalent of 100 current US dollars, but over the next 50 years decreased in price to approximately 20 current US dollars. This decrease is attributed to the increase in the ease of manufacturing associated with aluminium after Bayer, Hall, and Heroult’s discoveries. Sources United States Patent Application 20050238571: Process and apparatus for the production of alumina See also Electrometallurgy History of aluminium Hydrometallurgy References 1847 births 1904 deaths 19th-century Austrian scientists 20th-century Austrian scientists Austrian chemists