SiC- mullite brick is widely used in the upper and lower transitional zones of cement rotary kilns, due to excellent thermal shock resistance, and abrasion resist- ance. The investigation of different bauxites was mad...SiC- mullite brick is widely used in the upper and lower transitional zones of cement rotary kilns, due to excellent thermal shock resistance, and abrasion resist- ance. The investigation of different bauxites was made on the performance and micro-structure of SiC - mullite brick, especially thermal shock resistance. In two batches of bricks （ G1 and G2 ） , and two grades of bauxites （ L1 and I_2 ）, samples＇ physical and chemical properties were tested, and microstructure and phase composition were studied by SEM and XRD. The results show that raw material I2, containing large numbers of micro- pores smaller than 4 μm, has well developed mullite phase. While using L2 as aggregates and flues, SiC- mullite brick G2 has excellent thermal shock resistance. Therefore, for manufacture of SiC - mullite brick, not only chemical composition, bulk density and open porosi- ty of bauxite are important, but also its microstructure has to be considered, such as phase composition, crystal size and pore size distribution.展开更多
Corrosion of burning urban domestic wastes to alkali-resistant bricks and spalling-resistant high alumina bricks was researched by static crucible method and SEM in order to choose refractories for cement rotary kilns...Corrosion of burning urban domestic wastes to alkali-resistant bricks and spalling-resistant high alumina bricks was researched by static crucible method and SEM in order to choose refractories for cement rotary kilns for collaboratively disposing wastes. The result indicates that the main corrosion mechanism is slag permeation and corrosion ; the emitted high temperature gases containing alkali, sulfur and chlorine during burning the wastes re- act with refractories forming low melting point sulfate, chloride and compound salts, which metamorphose the refractories, and the loose metamorphic layer is easy to spall under thermal stress. So, corrosion resistance and spaUing resistance shall be taken into account when choosing refractories for cement rotary kilns for collaboratively disposing wastes. It is suggested that decomposition furnaces should adopt spaUing resistant high alumina bricks and anti-coating SiC castables, and preheating equipment should adopt high strength alkali-resistant bricks and castables.展开更多
文摘SiC- mullite brick is widely used in the upper and lower transitional zones of cement rotary kilns, due to excellent thermal shock resistance, and abrasion resist- ance. The investigation of different bauxites was made on the performance and micro-structure of SiC - mullite brick, especially thermal shock resistance. In two batches of bricks （ G1 and G2 ） , and two grades of bauxites （ L1 and I_2 ）, samples＇ physical and chemical properties were tested, and microstructure and phase composition were studied by SEM and XRD. The results show that raw material I2, containing large numbers of micro- pores smaller than 4 μm, has well developed mullite phase. While using L2 as aggregates and flues, SiC- mullite brick G2 has excellent thermal shock resistance. Therefore, for manufacture of SiC - mullite brick, not only chemical composition, bulk density and open porosi- ty of bauxite are important, but also its microstructure has to be considered, such as phase composition, crystal size and pore size distribution.
文摘Corrosion of burning urban domestic wastes to alkali-resistant bricks and spalling-resistant high alumina bricks was researched by static crucible method and SEM in order to choose refractories for cement rotary kilns for collaboratively disposing wastes. The result indicates that the main corrosion mechanism is slag permeation and corrosion ; the emitted high temperature gases containing alkali, sulfur and chlorine during burning the wastes re- act with refractories forming low melting point sulfate, chloride and compound salts, which metamorphose the refractories, and the loose metamorphic layer is easy to spall under thermal stress. So, corrosion resistance and spaUing resistance shall be taken into account when choosing refractories for cement rotary kilns for collaboratively disposing wastes. It is suggested that decomposition furnaces should adopt spaUing resistant high alumina bricks and anti-coating SiC castables, and preheating equipment should adopt high strength alkali-resistant bricks and castables.
