Effect Of Mullite Gradient Variation On The Performances Of Cold Ram Ming Paste Of Monolithic Lining Cathode Cell

The monolithic lining technology can reduce the occurrence of cracks in the cathode lining during the electrolysis process,avoiding the risk of leakage and prolonging the life of the aluminum reduction cell effectively.The monolithic lining technology has been applied very maturely in the yellow phosphorus furnace now.Inspired by it,it is proposed to build a monolithic furnace lining during the furnace construction of aluminum reduction cell.At present,the addition of a Si C material with a good high temperature resistance to the cold ramming paste of the cathode cell side,has the problem of product the lateral eddy currents and excessive power consumption in the electrolytic aluminum process.The sintering of Si C does not occurred phase transformation and volume change,low density,will reduce the service life of lining refractories.Therefore,this project intends to independently research and develop a new type of side cold ramming paste of cathode monolithic furnace,which is have a great significance for improving the production efficiency of aluminum reduction cells.Research indicates:（1）Andalusite begins to forming mullite at 1300°C,which increases with the increase of sintering temperature,and can increase the resistivity of the sample and reduce the porosity and shrinkage of the sample.（2）The addition of andalusite can reduce the porosity of the sample and increase its bulk density and true density effectively.And andalusite can produce volume expansion after sintering at high temperature,make up the shrinkage of carbonaceous material in cold ramming paste,reduce the generation of cracks,and the formation of mullite phase can improve the resistivity of the sample effectively.However,with the increase of andalusite content,the overall mechanical properties showed a decreasing trend.（3）The properties of cold ramming paste were further study,by adding a certain proportion ofα-Al₂O₃ on the basis of the addition of andalusite to further improve the performance,the results showed that,α-Al₂O₃ can reduced the content of the Si O₂glass phase which produced by andalusite mullization,promote the process of secondary mullitization of andalusite.Further reduced the porosity of the sample and increased the resistivity and expansibility of the sample.With the increase ofα-Al₂O₃content,the mechanical properties of the sample have been significantly improved.