Effect Of Bath Composition On Voltage During Anode Effect In 330 KA Aluminum Reduction Cells

Primary aluminum production is an energy intensive process.Electric energy cost is corresponding to 43%of the production cost.Due to continually increasing of electricity price,the production cost of aluminum increased significantly in recent years.In order to decrease the production cost,Guangxi Yinhai Aluminum Co.Ltd has to develop some technologies for aluminum reduction cells running at lower cell voltage with lower energy consumption.Based on the principle of aluminum electrolysis,the paper investigated the impact of bath composition on coefficient of anode effect.Through tests and discussion the impact of bath composition on cell voltage,alumina concentration on anode effect,and alumina feeding strategy on anode effect,which are related to lower cell voltage operation,lower bath temperature,lower superheat control,lower alumina concentration and lower coefficient of anode effect.We realized the goal of low cell voltage and energy consumption according to practice in 330kA aluminum reduction cells.The main conclusions are listed as following,The optimal controlling bands are aluminum fluoride extra 6%-12%,alumina concentration 1.0-3.0,superheat 7-10?.Stable alumina concentration control and superheat control are very important to the aluminum electrical reduction process.Narrow control band of materials balance,narrow control band of heat balance and MHD stability are the key factors for proper mass balance and energy balance of stable aluminum reduction cells.The average decrease of Max cell voltage during anode effect 7.65 V,the average decrease of anode effect voltage 7.8 mV,the average decrease of anode effect times 6.78,are realized in the aluminum electrical reduction process at the condition of above optimal controlling bands.