γ-Al_2O_3和α-Al_2O_3与其对应的氢氧化物对合成尖晶石的影响

Influence of γ-Al_2O_3 and α-Al_2O_3 and their corresponding hydroxides on synthesis of spinel

以γ-Al2O3(勃姆石在700℃保温4h热处理后的产物)、α-Al2O3(Al(OH)3在1400℃保温4h热处理后的产物)、勃姆石、Al(OH)3为原料,与轻烧MgO按n(Al2O3)∶n(MgO)=1的组成配料并制备试样,研究了在800～1600℃下不同氧化铝及其对应的氢氧化物对合成尖晶石的影响。结果表明:γ-Al2O3和α-Al2O3分别同与其对应的氢氧化物为原料的试样具有相似的烧结性能;且以氢氧化物为原料比以氢氧化物煅烧后所得的氧化物为原料更有利于尖晶石的生成,但不利于尖晶石的致密化。

Specimens were prepared by using γ-Al2O3 （ product of boehmite fired at 700℃ for 4 h） ,α-Al2O3 （ product of Al（OH）3 fired at 1 400℃ for 4 h） ,γ-AlOOH and Al（OH）3 as starting materials,mixed with light-burned MgO with proportion= n（Al2O3） ： n（MgO） = 1. The influence of different Al2O3 and their corresponding hydroxides on the synthesis of magnesia -alumina spinel was studied in the temperature range of 800 -1 600℃. The results indicated that the specimens prepared with γ-Al2O3 and α-Al2O3 and their corresponding hydroxides had similar sintering properties. Comparing the four starting materials, boehmite and Al（OH）3 had better effect for the synthesis of spinel but were unfavorable to the densification of spinel.