铝溶胶的制备条件对其凝胶成球性能的影响

Influence of alumina sol preparation conditions on its gelation and sphere formation ability

以硝酸和拟薄水铝石为原料制备了铝溶胶,考察了x(H+/Al摩尔比)和φ(六亚甲基四胺溶液与硝酸溶液的体积比)值对铝溶胶在油中凝胶成球性能的影响。使用氧化铝颗粒的Zingg指数对铝溶胶制备条件进行了评价。结果表明:铝溶胶和半透明铝溶胶的制备条件是x分别大于0.05和0.07;增大x和φ值均利于铝溶胶的凝胶化,但过大的x和φ值不利于溶胶收缩成球;Zingg曲线在1附近的平稳区间对应的x和φ值是合适的铝溶胶制备条件。

Alumina sol can be made by the reaction of nitric acid with pseudoboehmite. The effects of x （ molar ratio of H ^＋/A1） and φ （ volume ratio of hexamethylene tetramine solution with nitric acid solution） values on the gelation performance of alumina sol in the oil column were investigated by the Zingg factor of alumina granules. The results indicate that alumina sol and translucent alumina sol can be prepared when x is greater than 0.05 and 0.07 respectively; the increases of x and φ values are conducive to the gelation of alumina sol, but too large x and φ values may prevent the sol droplet from being transformed into sphericity; the suitable x and φ values for preparing alumina sol are corresponding to the curve range among which Zingg factor is closest to 1.