煅烧温度对工业氧化铝相变及活性的影响

Influence of calcining temperature on phase transformation and activity of industrial alumina

为了探究煅烧温度对工业氧化铝相变及活性的影响,将工业氧化铝分别在600、1 000、1 050、1 100、1 150、1 200和1 300℃保温2 h煅烧后,采用XRD和SEM分析物相组成和显微结构,并用激光粒度分析仪测定粒度和比表面积。结果表明:在600℃煅烧时,工业氧化铝中的γ-Al2O3逐渐转化为η-Al2O3和θ-Al2O3;在1 0001 150℃煅烧时,η-Al2O3和θ-Al2O3逐渐转化为α-Al2O3,α-Al2O3衍射峰逐渐增强,晶粒尺寸缓慢增大;1 200℃煅烧时,工业氧化铝颗粒表面裂纹最多,细磨后的粒度最小,活性最高。

To investigate the calcining temperature on phase transformation and activity of industrial alumi-na,industrial alumina was calcined at 600,1 000,1 050,1 100,1 150℃,1 200,or 1 300℃for 2 h and then the phase composition and microstructure of calcined samples were analyzed and characterized by XRD and SEM,respectively.Grain size and specific surface area after fine grinding were measured by a laser parti-cle size analyzer.The experimental results show that:after calcining at 600 ℃,γ-Al2 O3 in the industrial alu-mina gradually transforms into η-Al2 O3 and θ-Al2 O3;after calcining at 1 000-1 150 ℃,η-Al2 O3 and θ-Al2 O3 gradually transform into α-Al2 O3;the diffraction peak intensity ofα-Al2 O3 and grain size ofα-Al2 O3 increase gradually with calcining temperature rising;when calcined at 1 200 ℃,the industrial alumina has the most cracks on the particle surface,and is the finest and the most active particle after fine grinding.