摘要
为研究盐酸溶液处理对工业氧化铝煅烧过程中氧化铝相变的影响,采用pH分别为1、3和5的盐酸溶液处理细磨后的工业氧化铝,再将酸处理后的工业氧化铝分别在700、900、1 000和1 100℃下保温3 h煅烧,然后采用XRD和SEM对煅烧后试样的α相转化率、晶粒尺寸和显微结构进行表征。结果表明:随着盐酸溶液pH的降低,煅烧后试样中氧化铝的α相转化率逐渐增大,晶粒尺寸逐渐增大;当盐酸溶液的pH=1,于1 100℃煅烧时,能全部完成氧化铝的α相变,试样中α-Al_2O_3的晶粒尺寸为91 nm,有片状和蠕虫状结构产生,且团聚体数量较少。可见,工业氧化铝经过盐酸处理后,可以促进其在煅烧过程中的氧化铝α相变,改变晶粒尺寸,降低团聚体颗粒。
The commercial alumina after ball milling was treated using hydrochloric acid with the controlled pH value at 1,3 and 5,then calcined at 700,900,1 000 and 1 100 ℃ for 3 h,respectively,to study the effects of hydrochloric acid on the phase transformation of commercial alumina during calcination. The alpha phase transformation conversion rate,crystal size and microstructure of specimens were investigated by XRD and SEM.The results show that with the pH value of hydrochloric acid decreasing,the alpha phase transformation conversion rate and crystal size increase gradually. When the pH value of hydrochloric acid is 1 and the calcination temperature reaches 1 100 °C,the alpha phase transformation of alumina is com-plete and the crystal size of α - Al2O3 reaches 91 nm, the layered and vermicular α - Al2O 3 crystals are formed,and there are a small amount of aggregates in the specimens. It can be deduced that the treat-ment of hydrochloric acid can promote alpha phase transformation of alumina during the calcination, change the crystal size of α - AL203 and decrease the amount of aggregates.
出处
《耐火材料》
北大核心
2017年第3期186-190,共5页
Refractories
基金
国家自然科学基金资助项目(51502213)
关键词
工业氧化铝
α相变
盐酸
pH
显微结构
晶粒尺寸
alumina
α-phase transformation
hydrochloric acid
pH value
microstructure
crystal size
