Analysis of the overall energy intensity of alumina refinery process using unit process energy intensity and product ratio method

摘要: Abstract Alumina refinery is an energy intensive industry. Traditional saving methods employed have been single-equipment-orientated. Based on two concepts of ‘energy carrier’ and ‘system’, this paper presents a method that analyzes the effects unit process intensity (e) product ratio (p) overall alumina. The important conclusion drawn from it necessary to decrease both ratios in order alumina, which may be taken as future policy for saving. As case study, Chinese Zhenzhou alumina plant with Bayer–sinter combined between 1995 2000 was analyzed. result shows decreased by 7.36 GJ/t-Al2O3 over period, 49% total due direct saving, 51% indirect emphasis decreasing high-energy consumption processes, such evaporation, slurry sintering, aluminium trihydrate calcining desilication. Energy savings can made (1) increasing proportion Bayer digestion, (2) grade ore dressing or importing some rich gibbsite (3) promoting advancement technology.