Profile: Karl Bayer - Extraction of Alumina from Bauxite

This post is a part of the 12 Chemical Engineers who Changed the World series.

Aluminium was once so expensive that an aluminium bar was displayed next to the French Crown Jewels in Paris in 1855. Karl Bayer was an Austrian chemist who developed a process for extracting alumina from bauxite, and along with the Hall-Heroult process was able to reduce the cost of producing aluminium to drop by 80% from 1854 to 1890.

Bayer was born in 1847 in Bielitz, Austria. He studied chemistry at the University of Heidelberg before he began working for the Tentelev Chemical Plant.

He discovered a method for producing aluminium hydroxide as a dye for the textile industry in 1887 and patented it the next year. The process was made of three key discoveries:

  1. Adding aluminium hydroxide precipitation yield could be maximized if agitated in a cold solution with recycled seed. The solids can then be easily filtered and washed to produce a pure product
  2. Alumina within bauxite could be extracted by heating it in a solution of sodium hydroxide (caustic soda)
  3. The spent caustic soda could be easily recycled

The Bayer process is still used throughout the world as the primary method for producing smelter grade alumina. The first alumina refinery using the bayer process was at Gardanne in France in 1894 and is still operating today.

Karl Bayer made a huge impact on the minerals processing industry, as well as modern culture as a whole. The ability to produce aluminium at a much lower cost than previously boosted its use and popularity and is still used extensively throughout the world.



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