Relationship Between Metal Weight And Side-ledge Profile In Aluminum Electrolysis Pot

Aluminum industry is an energy intensive process.Energy saving and long service life of electrolytic pots are very important for the process.In last decade,some new technologies and operation strategy were recognized and applied widely by the aluminum industry.We need a deep understanding of the aluminum electrolysis to meet the requirement of new situation.In this paper,some industrial tests were carried out to investigate the relationship between metal weight and side-ledge profile in the cell.The tests were conducted on three different cell technologies.Some conclusions were obtained as following:(1)In the case of 240 kA new structure cathode cell,proper metal weight during cell start is in the range of 11 to 12 tons.Under such condition,cell could have good performance because of stable thermal balance,which enables the stable side-ledge profile of the cell.(2)In the case of amperage increasing from 240 kA to 248 kA,addition of 1.6 to 1.8 tons of aluminum is necessary for holding thermal balance if cell voltage kept constant.Such operation is benefit for stable operation of the cells.(3)In the case of amperage decreasing for 240 kA prebaked cell,the cell went into cold status if metal weight was not adjusted.Though it is benefit for long service life of cell,anodes at the corners of the cell have poor performance because of poor magnetic field design.(4)In the case of secondary start of 240 kA prebaked cell,metal level of 17.5 cm(aboutl4.5 tons aluminum)is necessary for stable operation.Bath temperature control will ensure the clean cathode and good size of side ledge,which is benefit for stable solid ledge of the cell.The above industrial practices improve our understanding of the aluminum electrolysis process and enable the generation of new technology,which will be benefit for operators of the aluminum industry.