Study On The Influence Of High Temperature Calcination Of Bauxite Based Homogeneous Clinker On The Structure And Properties Of Materials

In recent years bauxite based homogeneous grogs have become the main raw materials of high alumina refractories with the development of the refractory industry in China.The raw materials,components and preparation process of bauxite based homogenized grogs are quite different in the market.More attention to the uniformity of the components are paid to the bauxite based homogenized grogs with instable performances produced in the factories,but ignored the uneven microstructure.There is a lack of in-depth research on the application and popularization of bauxite based homogenized grogs,the study of properties,and the relationship between the structure and properties of materials.Therefore,it studied the effect on the structure,properties and the relationship between them of the materials by high temperature calcination of bauxite based homogenized clinker in this work.And it is hoped that it can be used for reference for the popularization and application of bauxite based homogeneous grogs in the future.In this work,it studied the effect on the bulk density,apparent porosity,thermal expansion,thermal shock resistance,phase composition and microstructure of bauxite based homogeneous clinker by high temperature calcination of the homogeneous clinker.And then according to the content of Al₂O₃,it designed the matrix samples used the bauxite based homogeneous clinker without high temperature calcination and calcined by different calcination systems as the main raw materials with brown corundum and Guangxi white mud.After pressed and fired,the properties of the matrix samples were tested.At last,the samples were prepared with the bauxite based homogeneous clinker without high temperature calcination and calcined by different calcinations systems as aggregates and the above corresponding matrix.After fired,the properties were tested and the microstructure was observed.The effect of the microstructure and properties of the materials by high temperature calcination of bauxite based homogenized clinker was investigated.The experimental results are as follows.?1?By calcining the bauxite based homogeneous clinker at different calcination systems,the bulk density of the particles increases and the apparent porosity decreases.The bauxite based homogenized clinker particles are mainly composed of mullite and corundum.The glass phase in the bauxite based homogeneous clinker before calcination disappears after calcination at high temperature,and the growth of mullite crystals is better.?2?The effect of high temperature calcination of bauxite based homogeneous clinker on the properties of matrix was studied.The higher the Al₂O₃ content,the larger the bulk density,the smaller the apparent porosity.The structure of the samples made from bauxite based homogeneous clinker without high temperature calcination is slightly denser than that of the samples made from bauxite based homogeneous clinker after calcination.Before and after thermal shock,the elastic modulus of series samples increases with the increase of Al₂O₃ content.?3?The effect of the microstructure and properties of materials by high temperature calcination of bauxite based homogeneous clinker was studied.With the increase of Al₂O₃ content in matrix,the bulk density of the sample becomes larger and the apparent porosity decreases.Samples with higher Al₂O₃ content in matrix have higher normal temperature flexural strength and normal temperature compressive strength,higher high temperature flexural strength and better thermal shock resistance.With the increase of the calcining temperature of the bauxite based homogeneous clinker,the bulk density of the samples is getting smaller,the apparent porosity is getting higher,and normal temperature flexural strength and normal temperature compressive strength is getting smaller.According to the microstructure,there are different forms of bridge structure at the interface between particles and matrixs of the samples made of bauxite based homogeneous clinker without high temperature calcination.