基于低成本和废料资源化利用的目的,以质量分数分别为31.8%的煤矸石,68.2%的氢氧化铝,外加3%的金属氧化物(V2O5MnO2或MgO)为添加剂,于1500℃保温1h煅烧后制备了莫来石晶须增强刚玉耐火材料试样,并与未添加金属氧化物的试样对比。采用XRD、SEM等对试样物相及显微结构进行了分析,并探讨了添加不同金属氧化物对莫来石晶须生长和长径比及试样性能的影响。结果表明:添加金属氧化物后,莫来石晶须的长径比都出现了下降,其中添加V2O5的试样对晶须长径比的影响最小,MnO2次之,添加MgO的试样影响最大。当添加金属氧化物MnO2时,试样具有最大的抗折强度,这主要是由于试样中莫来石晶须长径比合适(13.5),以及莫来石是主晶相,刚玉是次晶相所致。
For low cost and waste resource utilization,corundum refractories reinforced by mullite whiskers were prepared by using 31.8% coal gangue and 68.2% aluminum hydroxide as starting materials,extra- adding 3% metal oxides (V205, MnO2 or MgO), and firing at 1 500℃ for ] h. The specimens without adding metal oxide were used for reference. The chemical composition and microstructure of the speci- mens were characterized by XRD,SEM ,etc. Effects of metal oxides on the growth and the ratio of length to diameter of mullite whiskers,and the properties of the specimens were studied. The results show that after adding metal oxides,the ratio of length to diameter of mullite whiskers of all the specimens decreases,in which the effect of V2O5 is the smallest,MnO2 is the next,MgO is the largest. The specimen with MnO2 exhibits the optimum modulus of rupture,contributed by suitable ratio of length to diameter (13.5),the main phase mullite and the second phase corundum.