| 摘要 |
<p>1,225,355. Moulding refractory bricks. DIDIER-WERKE A.G. 30 May, 1968 [5 June, 1967], No. 25733/67. Heading B5A. [Also in Divisions C1 and F4] Bricks of silica refractory material are made by subjecting a mixture containing more than 95% by weight SiO 2 and up to 3% CaO to a pressure which increases for a period of at least 10 seconds to at least 700 kg. per sq. cm. Air is allowed to escape and the compressed mixture is fired at a temperature which increases slowly to a maximum of at least 1300‹ C. and preferably increases gradually from 1300‹ to 1500‹ C. The temperature is held at the maximum for at least 35 hours.</p> |
