Sintered mullite is prepared by kyanite powder with Al_2O_3 content of 45% and 50%(Yinshan, Nanyang City, China),and the industrial alumina is added to control the chemical composition. The different series of sintere...Sintered mullite is prepared by kyanite powder with Al_2O_3 content of 45% and 50%(Yinshan, Nanyang City, China),and the industrial alumina is added to control the chemical composition. The different series of sintered mullite according to the Al_2O_3 content(45%-70%) are designed. The raw materials are mixed and compacted, and then sintered at different temperatures. Physical properties, phase composition, microstructure and refractoriness under load of the synthesized samples are characterized by physical property test, XRD, SEM and RUL test, in order to confirm the quality of sintering and the relationship between temperature and mullitization reaction. The results show that the sintered mullite from low-medium grade kyanite has well developed mullite crystals and a continuous staggered network structure is formed, which has a significant contribution to increasing the high temperature performance of mullite.展开更多
In order to improve the thermal shock resistance of chrome-corundum bricks,different amounts of andalusite were added to the formulation of chrome-corundum bricks to replace the equivalent white fused corundum with th...In order to improve the thermal shock resistance of chrome-corundum bricks,different amounts of andalusite were added to the formulation of chrome-corundum bricks to replace the equivalent white fused corundum with the same particle size.After mixing,shaping,drying and firing,the density,the cold strength,the cold wear resistance,the hot modulus of rupture and the thermal shock resistance were tested.XRD,SEM and elemental surface scanning were used to characterize the specimens.The results show that:(1)the volume expansion of andalusite mullitization reduces the apparent porosity of chrome-corundum bricks;(2)the density and the hardness of mullite are lower than those of corundum so the decrease of the corundum content in brick leads to the decrease of the bulk density,the strength and the cold wear resistance;(3)the cross-distributed columnar mullite in the matrix can effectively improve the hot modulus of rupture and the thermal shock resistance of the specimens;(4)considering comprehensively,the andalusite addition shall not exceed 18%.展开更多
In order to realize the large-scale and high-value utilization of waste architectural ceramics,high-temperature resistant materials based on waste architectural ceramics were prepared with sodium silicate as the binde...In order to realize the large-scale and high-value utilization of waste architectural ceramics,high-temperature resistant materials based on waste architectural ceramics were prepared with sodium silicate as the binder,clay/bauxite and metakaolin/bauxite as coating materials,and the cold strength obtaining mechanism was explored.The phase composition,the microstructure and the mechanical properties of the high temperature resistant materials based on waste architectural ceramics were tested and analyzed.The results showed that when the heat treatment temperature was between 110-1000℃,the strength of the samples mainly came from the physical adhesion of sodium silicate and fine powder.When the temperature rose to 1100℃,the strength of the sample was improved since the internal low-melting-point components melted and promoted sintering.The addition of clay and bauxite can effectively enhance the flexural strength of the samples when the heat treatment temperature is 1000℃.When the heat treatment temperature rises from 900 to 1000℃,the flexural strength of the samples will be enhanced owing to the formation of silica alumina spinel and mullite from metakaolin.展开更多
The progress of research and production of bauxite based homogenized grogs in China was summarized and the achievements of their application and modification in recent years were epitomized.In combination with the sho...The progress of research and production of bauxite based homogenized grogs in China was summarized and the achievements of their application and modification in recent years were epitomized.In combination with the shortcomings existing in the research,production and application,the suggestions of bauxite based homogenized grogs for future development were put forward.展开更多
Preparation of bauxite-based sintered mullite homogenized grog was introduced and its application in ladle castable was studied.Two kinds of bauxite-based sintered mullite homogenized grogs were used,named as GA and G...Preparation of bauxite-based sintered mullite homogenized grog was introduced and its application in ladle castable was studied.Two kinds of bauxite-based sintered mullite homogenized grogs were used,named as GA and GB,respectively.The results show that bauxitebased sintered homogenized grog with uniform components,stable microstructure and mullite as main crystal phase can be prepared using joint process of three-step homogenization,automatic component batching,wet cogrinding,high-temperature calcinations.It also indicates that carbon steel ladle castables with GA or composite aggregate of GA and GB as main materials have the same excellent general performance indicators,great erosion resistance,anti-strip performance and longer service life in field applications,and compared with castables with single aggregate of GA,the castables with aggregate of GA and GB as main materials had higher cost performance because of lower bulk density of GB.展开更多
文摘Sintered mullite is prepared by kyanite powder with Al_2O_3 content of 45% and 50%(Yinshan, Nanyang City, China),and the industrial alumina is added to control the chemical composition. The different series of sintered mullite according to the Al_2O_3 content(45%-70%) are designed. The raw materials are mixed and compacted, and then sintered at different temperatures. Physical properties, phase composition, microstructure and refractoriness under load of the synthesized samples are characterized by physical property test, XRD, SEM and RUL test, in order to confirm the quality of sintering and the relationship between temperature and mullitization reaction. The results show that the sintered mullite from low-medium grade kyanite has well developed mullite crystals and a continuous staggered network structure is formed, which has a significant contribution to increasing the high temperature performance of mullite.
文摘In order to improve the thermal shock resistance of chrome-corundum bricks,different amounts of andalusite were added to the formulation of chrome-corundum bricks to replace the equivalent white fused corundum with the same particle size.After mixing,shaping,drying and firing,the density,the cold strength,the cold wear resistance,the hot modulus of rupture and the thermal shock resistance were tested.XRD,SEM and elemental surface scanning were used to characterize the specimens.The results show that:(1)the volume expansion of andalusite mullitization reduces the apparent porosity of chrome-corundum bricks;(2)the density and the hardness of mullite are lower than those of corundum so the decrease of the corundum content in brick leads to the decrease of the bulk density,the strength and the cold wear resistance;(3)the cross-distributed columnar mullite in the matrix can effectively improve the hot modulus of rupture and the thermal shock resistance of the specimens;(4)considering comprehensively,the andalusite addition shall not exceed 18%.
基金the National Key R & D Program of China (2018YFC1901501, 2018YFC1901503 and 2018YFC1901504)
文摘In order to realize the large-scale and high-value utilization of waste architectural ceramics,high-temperature resistant materials based on waste architectural ceramics were prepared with sodium silicate as the binder,clay/bauxite and metakaolin/bauxite as coating materials,and the cold strength obtaining mechanism was explored.The phase composition,the microstructure and the mechanical properties of the high temperature resistant materials based on waste architectural ceramics were tested and analyzed.The results showed that when the heat treatment temperature was between 110-1000℃,the strength of the samples mainly came from the physical adhesion of sodium silicate and fine powder.When the temperature rose to 1100℃,the strength of the sample was improved since the internal low-melting-point components melted and promoted sintering.The addition of clay and bauxite can effectively enhance the flexural strength of the samples when the heat treatment temperature is 1000℃.When the heat treatment temperature rises from 900 to 1000℃,the flexural strength of the samples will be enhanced owing to the formation of silica alumina spinel and mullite from metakaolin.
文摘The progress of research and production of bauxite based homogenized grogs in China was summarized and the achievements of their application and modification in recent years were epitomized.In combination with the shortcomings existing in the research,production and application,the suggestions of bauxite based homogenized grogs for future development were put forward.
文摘Preparation of bauxite-based sintered mullite homogenized grog was introduced and its application in ladle castable was studied.Two kinds of bauxite-based sintered mullite homogenized grogs were used,named as GA and GB,respectively.The results show that bauxitebased sintered homogenized grog with uniform components,stable microstructure and mullite as main crystal phase can be prepared using joint process of three-step homogenization,automatic component batching,wet cogrinding,high-temperature calcinations.It also indicates that carbon steel ladle castables with GA or composite aggregate of GA and GB as main materials have the same excellent general performance indicators,great erosion resistance,anti-strip performance and longer service life in field applications,and compared with castables with single aggregate of GA,the castables with aggregate of GA and GB as main materials had higher cost performance because of lower bulk density of GB.
