Bayer's Process for Alumina Production: a Historical Perspective

The Bayer Process (for alumina) as we know it today involves two steps: • The pressure leaching of bauxite with NaOH solution to obtain sodium aluminate solution. • The precipitation of pure aluminum hydroxide from this solution by seeding with fine crystals of Al(OH)3 . The leaching step was invented five years after the precipitation step (Table 1), and the precipitation step was an improvement to the Le Chatelier Process (l), namely replacing CO2 by the seed (Fig. I). In 1888 a British Patent entitled "A Process for the Production of Aluminum Hydroxide" was issued Chatelier (I850-I936) is best known for the thermodynamic principle which bears his name. Bayer (2) was born in Bielitz, a few kilometers southwest of Cracow in Silesia, at that time a Province of the Austrian Empire, now in Poland. The map of Europe at that time was quite different from what we know it today. It was the age of empires: the British, French, German, Russian, Ottoman, and Austrian empires. The Austrian Empire was composed of a vast territory encompassing the present day Austria, northern Italy, Bohemia, and Moravia which are parts of present-day Czechoslovakia, Hungary, Transylvania (a part of present-day Romania), Croatia, Dalmatia and Bosnia