REVIEW ON THE ENERGY SAVING TECHNOLOGIES APPLIED IN BAYER PROCESS IN CHINA

Gu S, Wu J

The energy saving technologies applied in Chinese Beyer refineries in recent years are reviewed in this paper. The Bayer process in Chinese refineries is systematically optimized by cycling efficiency improvement and liquor concentration difference reduction. A series of key technologies for intensifying the processes and reducing unit energy consumption are developed and applied, such as indirect preheating for digestion, multi-effect falling film evaporating and gas suspension calcining etc. The more efficient equipment including efficient high pressure pumps and centrifugal pumps, energy saving agitators and fans etc is widely used for lower power input. The surplus heat in the waste vapor, cycling liquor and hot solid materials in the process is more and more recovered. The application of some additives promotes energy consumption reduction. The technologies mentioned above and widely applied result in a great progress for the Chinese refineries to reduce energy consumption in the past 10 years.