| 摘要 |
<p>TITLE A METHOD OF MAKING A CELLULAR BODY FROM A HIGH SILICA BOROSILICATE COMPOSITION An intimate mixture of an amorphous silica (preferably an amorphous, precipitated hydrated silica) potassium oxide, boric oxide, alumina and a cellulating agent is prepared. The intimate mixture is thereafter subjected to a temperature of between about 1390.degree.C to 1450.degree.C for a sufficient period of time to coalesce the mixture and gasify the cellulating agent and form a cellular body having a substantially uniform cell structure. In one embodiment the intimate mixture is prepared by first forming a slurry of the constituents and thereafter drying the slurry to form aggregates. The dried aggregates are thereafter comminuted if necessary to a suitable size to form a pulverulent batch. The pulverulent batch is subjected to a cellulating temperature in a cellulating furnace and forms a foam-like mass. The foam-like mass is comminuted to a suitable size to form a precellulated material. The precellulated material is thereafter intimately mixed with additional cellulating agent and pulverulent batch in preselected proportions and subjected to cellulating temperatures in the cellulating furnace where the constituents coalesce and gasify the cellulating agent to form a cellular body having a substantially uniform cell structure. In another embodiment alumina, boric oxide, an alkali metal salt and a cellulating agent are comminuted and intimately mixed in a ball mill to form a first mixture. Thereafter, amorphous silica (preferably an amorphous, precipitated hydrated silica) is added to the first mixture to form a second mixture or batch that contains more than 80% by weight amorphous silica. The second mixture is milled in the ball mill and thereafter the second mixture is subjected to a temperature sufficient to coalesce the second mixture and gasify the cellulating agent to form a cellular body having a substantially uniform cell structure. A preselected portion of the trimmings from the cellular body may be added to and comminuted with the first mixture before the amorphous silica is added to the first mixture to form the second mixture.</p> |
