Unfired refractory bonded with feldspathoid material - formed by reacting clay and alkali, mixing with refractory and heating at low temp

摘要

In the mfr. of refractory articles, intergranular bonding is obtd. using a synthetic felspathoid material, obtd. by reaction between a clay and an alkali in a few mins. at 100-200 degrees C. The felspathoid material is mixted with the refractory material in amts. of 1-5 wt.% as a dry powder. The refractory articles can be made without a firing step yet can be used at 1400 degrees C. Pieces of large dimensions and of complicated shapes can be produced in reproducible shapes and sizes without unpredictable shrinkages and crystallographic transformations etc. Used for saggars and other plates for firing ceramics, for cores for metal castings, etc.