NABALOX® K 85 a synthetic refractory grain, contains at minimum 85% AI2O3 and about 14 % SiO2. As a result of this high AI2O3 content and a low ration of secondary components of max. 1 % a high refractoriness is ensured. Due to the high synthesis temperature, close to the theoretical melting point of about 1850 °C, the material has a low open porosity accompanied with a low water absorption and a phase component of at least 50 % high refractory corundum.

This material offers a high-quality, synthetic alternative to less pure refractory raw materials, such as those of the sillimanite group or the raw materials sintered bauxite and brown fused corundum. In terms of refractoriness, K 85 belongs to the group of white, synthetic raw materials as well as the synthetic sintered Mullite (SYMULOX® M 72) and tabular aluminas and their fused derivates. The synthetic raw material K 85 is an excellent base as a main component for shaped and unshaped AI2O3-rich refractory products with application temperatures up to 1800°C.

High temperature creep and corrosive attack in refractories is based mainly on the matrix properties. Reasoned by lower porosity of the refractory grain related to its high production temperature. For this reason, for refractory products containing even small amounts of SiO2** in the matrix, K 85 can be used as a supporting  grain without any degradation of high temperature properties as compared to e. g. tabular alumina. Moreover K 85 has, due to its phase composition, a lower density and thermal conductivity than pure alumina. These unique advantages are based on reduced heat loss of high-temperature facilities. Standard delivery size are pellets > 8 mm.

**(e. g. microsilica for deflocculated corundum concretes, kaolin as a pressing aid for corundum- or other mullite-ceramic bonds).

Properties