胶溶条件对拟薄水铝石酸分散性及成球性能的影响

采用拟薄水铝石粉体分散法制备氢氧化铝溶胶，研究胶溶条件对拟薄水铝石酸分散指数的影响，发现反应温度和酸加入量对拟薄水铝石酸分散指数影响较大，反应时间对其影响较小。将不同反应温度下制备的氢氧化铝溶胶通过油氨柱成型，经干燥、焙烧工艺制备球形氧化铝载体，采用BET、XRD表征氧化铝球的物化性能，结果表明，随着氢氧化铝溶胶制备温度的升高，所得氧化铝球的比表面积改变不大，孔体积有所降低，孔径分布更加集中，堆密度有所升高，压碎强度逐渐增大。水热稳定性实验结果表明，经650 ℃、水蒸气处理50 h后自制氧化铝球的比表面积与工业用氧化铝球的比表面积接近，二者的水热稳定性相当。

EFFECT OF PEPTIZATION CONDITIONS ON THE DISPERSITY AND PELLETIZATION OF PSEUDO-BOEHMITE

Aluminum hydroxide sol was prepared by method of dispersing pseudo-boehmite powder in acidic water.The effect of peptizing conditions on the acid dispersion index of pseudo-boehmite was studied,and it was found that the reaction temperature and acid amount had great effect while the influence of reaction time was not significant.Using aluminum hydroxide sol samples obtained under various reaction temperatures,spherical alumina supports were prepared by oil-ammonia column shaping method and followed by drying and calcination.The results of characterization by BET and XRD showed that with the increase of sol prepared temperature,for the prepared alumina support,its pore volume decreased,the distribution of pore diameter was more concentrated,bulk density and crush-strength increased,and the specific surface area changed little.Results of hydrothermal stability test at 650 oC for 50 h showed that the specific surface area of treated self-made alumina spheres was close to that of treated industrial one,which indicated that they possessed the similar hydrothermal stability.