| 摘要 |
<p>Hydrated clay prepd. by usual methods is activated by heating it at a rate of 2-200 (12-80) degrees C/min. to 300-460 degrees C until 'boiling' (visible evolution of water vapour) is completed, then applying vacuum of 20-750 (100-250)mm. for not 3 min. The process is suitably carried out by introducing the clay into a vacuum oven pre-heated to 450 degrees C and applying vacuum at the appropriate moment. If the oven temp. is lower, higher vacuum and longer exposure to it is needed. The combined water content of the activated clay is typically 2.25%.</p> |
