Large-scale Equipment In Alumina Production By Bayer Process

Based on the practical production, by means of optimizing process, using advanced technology equipments and large-scale equipments and compact arrangement, this thesis discusses the energy saving and emission reduction of the Bayer process alumina refinery. The main contents of this study are shown as follows:Firstly, using the Φ4.5×8.5m raw mill, which is the max working size of domestic aluminum industry. Secondly, the single line of red mud settling and washing reaches the industry’s biggest capacity of one million tons of alumina per year. Thirdly, the processing capacity of gibbsite-type bauxite of digestion apparatus group reaches500thousand tons of alumina per year and it is the max working size of domestic aluminum industry. Fourthly, the capacity of3000tons of alumina everyday calcinator is the largest complete sets of equipment of domestic aluminum industry. By means of large-scale equipments and optimized layout, compared with the Aluminum Industry Standard, kinds of production indexes have been improved. Such as:alumina total recovery is achieved77.24%and which is2.24%higher than that of industry standards; power consumption is180kWh/t-Al2O3and saves electricity40kWh/t-Al2O3; fresh water consumption is0.5t/t-Al2O3and which is only1/6of that of industry standards; new steam consumption is1.66t/t-Al2O3and which is about1/2of that of industry standards; compared with industry standards, the comprehensive energy consumption comes down by30%to9.74GJ/t-Al2O3and which is2.5GJ less than that of the domestic other similar project. By significantly reducing energy consumption, the process is in line with national industrial policy of energy saving and emission reduction. Also the technical and economic indexes are superior to that of the Aluminum Industry Standard Conditions and in the industry leading level.