以用后Al2O3-C滑板砖、用后硅砖和用后黏土砖为原料合成莫来石,研究了原料种类(用后滑板砖+用后硅砖、用后滑板砖+用后黏土砖),Al2O3、SiO2摩尔比(3.5:2、3:2和2.5:2)和合成温度(1550、1600℃)对合成莫来石材料的相组成、显微结构和抗折强度的影响。结果表明:1)以用后滑板砖+用后硅砖或用后滑板砖+用后黏土砖为原料,在1550或1600℃保温4h均可以合成出莫来石材料。2)最适宜的合成工艺参数为:以用后滑板砖和用后黏土砖为原料,按Al2O3、、SiO2摩尔比为3.5:2配料,在1600℃保温4h煅烧。3)以最适宜的工艺参数合成的试样中,主晶相莫来石的相对含量达96.3%,次晶相为少量的刚玉,无石英相存在;莫来石晶体的长径比大,彼此均匀交联,结构较为致密;试样的抗折强度达65MPa。
The specimens were prepared using wasted Al2O3 -C slide gate,wasted silica bricks and wasted fireclay bricks as starting materials. Effects of various materials (wasted slide gate + wasted silica bricks,wasted slide gate +wasted fireclay bricks) ,molar ratio of Al2O3 and SiO2(3.5:2,3:2 and 2.5:2) and synthesizing temperature (i 550 and 1 600 ℃) or〉 phase composition, microstructure and crushing strength of synthesized mullite were studied. The results showed that, mullite can be synthesized using wasted slide gate + wasted silica bricks or wasted slide gate +wasted fireclay bricks at 1 550℃ or 1 600℃ for 4 h. The optimum synthesis technical parameters:using wasted slide gate +wasted fireclay bricks as starting materials, molar ratio of Al2O3 and SiO2 was 3.5:2,calcined at 1 600℃ for 4 h. In the specimens produced using the optimal synthesis technique parameters,the main crystal phase was mullite, about 96.3% ,the second crystal phase was a little corundum,there was no quartz. The formed mullite crystals had large length-diameter ratio and interlocking network structure,and the crushing strength was about 65 MPa.