摘要 |
<p>An aluminum salt solution and an alkali aluminate solution are subjected to a neutralization reaction to produce a precipitate of a pseudoboehmite powder. The neutralization reaction is carried out under conditions of a reaction temperature of 55 to 71 °C, a pH value of 8.5 to 9.5, and a liquid feed time of 7 to 25 min. The resultant pseudoboehmite has a volume of pores with diameters of 20 to 600 Å ranging from 0.8 to 1.8 cc/g as measured by the nitrogen adsorption method and the maximum value of the change ratio of the pore volume to the pore diameter, dV/dD, of at most 0.018 cc/g.Å as determined by the BJH method. The use of this pseudoboehmite can realize the preparation of a hydrorefining catalyst carrier that has a sharp pore diameter distribution and, when immersed in a catalyst solution, is less likely to cause a lowering in strength.</p> |