| abstract |
The present invention pertains to an improved process for the preparation of quasi-crystalline boehmite. In this improved process a quasi-crystalline boehmite precursor is aged at a pH below 7, preferably under hydrothermal conditions. It was found that when conducting the preparation processes for quasi-crystalline aluminas described in the prior art at a pH below 7 and under hydrothermal conditions instead of the high pH and thermal ageing used in the prior art, QCBs with higher crystallinity are obtained. In the process according to the invention additives may be added to the quasi-crystalline boehmite precursor. This results in a high quality QCB with additives in a homogeneously dispersed state. Suitable additives are compounds containing elements selected from the group of rare earth metals, alkaline earth metals, transition metals, actinides, silicon, gallium, boron, and phosphorus. |