| 摘要 |
A method of manufacturing beta alkaline alumina parts and in particular beta sodium alumina parts in which the following successive steps are carried out: A. Alumina powder and an alkaline carbonate powder are intimately mixed together in quantities such that a predetermined ratio Al2O3/Na2O is obtained; B. Said intimate mixture is heated in an open crucible; C. Said mixture is allowed to cool freely; D. The powder thus obtained is crushed; E. Said parts are shaped; and F. Said parts are sintered; said parts being disposed for this purpose in a sintering chamber, which is at least partially made of a refractory material which includes a mixture of three ingredients, namely beta alumina fire clay obtained by melting and crushing into grains with a grain size of about 0.5 mm, beta alumina cement or binding agent obtained from an alpha alumina and sodium carbonate mixture by reaction in the solid state and at a temperature of about 1200 DEG C., such a cement having a grain size of about 10 microns and lastly a sodium salt, the respective proportions by weight of these three ingredients being such that during sintering said chamber generates an atmosphere rich in sodium in the immediate vicinity of the parts. |
