ENERGY CONSUMPTION IN THE BAYER PROCESS

Mach T

In the Bayer process, cost pressures associated with fuel consumption for steam generation and gibbsite calcination has led to an increased focus on efficient energy use and recovery. Additionally, with the Clean Energy Bill passing through the the Australian Parliament, the focus on greenhouse gas emissions associated with fossil fuel combustion in Australia, is further driving the need for energy reduction initiatives. Whilst significant improvements have occurred, further energy reduction opportunities are required to continue to meet community and business expectations, and to move the optimum energy cost closer to fundamental and technical limits. This paper details a systematic approach to cataloguing energy flows and losses throughout the Bayer Process, and details methods for identifying further energy reduction initiatives. This approach has assisted the identification of energy efficiency opportunities in Rio Tinto Alcan’s existing operations, and provides a foundation for the development of a sub 6GJ/t Alumina Refinery flow sheet for a future Greenfield refinery.