ES426593A3 - Procedure for the manufacture of expansioned ceramic materials, in the form of grain. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Process for the manufacture of expanded ceramic materials, in the form of grain, characterized in that the starting material, which is composed of at least 25% by weight parts of mineral-forming gas materials, such as swellable clay, clay slate or a volcanic earth, like pumice stone, of mineral materials such as sea sand or sandstone, with a content of sio2, which exceeds 65 parts by weight, and an addition of caustic soda (naoh) after grinding, mixing and homogenization, with addition of water, it is molded into tablets that in the wet state, by introduction by rolling or rolling are completely surrounded with a layer of cement, after which, these tablets, in a desiccant oven, for a time of 20 minutes, dry and heat at temperatures, which rise to a maximum of -700º c, then, with a temperature rise as quickly as possible, they are heated in a baking oven in the duration of at least 3 to 5 minutes at temperatures of 1,000 to 1,200ºC and then cooled slowly to below 550º c, to obtain a ceramic material in the form of grain, which presents a uniform structure of bubbles, in which the intermediate partitions and strips between the bubbles, they consist of a solidified fusion, essentially free of bubbles, in which they are inserted, forming a framework, crystallites with a high content of silicon, and which is surrounded by a solid, rough, cement shell. (Machine-translation by Google Translate, not legally binding)