The Co-Editors of this book have a slightly different perspective on the recovery of alumina from bauxite. Benny and Fred received their technical training as MS Chemical engineers. Benny Raahauge was employed by FL Schmidt and thus represented a manufacturer and seller of equipment used in that industry. Fred Williams was employed by Alcoa and was assigned management responsibilities in alumina processing research, plant process engineering and running plant production. Both individuals have conceived technical improvements to the alumina recovery process as recognized by patents and technical awards, written and presented numerous papers at international technical meetings and have served as chairmen and organizers of international technical sessions. The authors of the individual chapters in this book are noteworthy experts from around the world in alumina manufacturing and research technology.