摘要 |
<p>Dry ready mix for preparing acid-resistant cements contains condensed aluminium phosphate as a hardener with a molar ratio of P2O5 : Al2O3 or 1.1 to 3, it is obtained from an acid aluminium phosphate or this molar comp. by heating in a first stage to max. 400 degrees C, up to constant weight, and in a second stage up to max. 750 degrees C. Specifically, the hardener is rendered hydrophobic with a mineral oil.</p> |