CERAMICS IN THE Na2O–CaO–SO3 SYSTEM AS A PROMISING INORGANIC POROGEN

Abstract

Ceramics with phase composition after firing in the range of 600 – 900 °C represented by anhydrous calcium sulfate CaSO4, and calcium sodium sulfates (Na0,8Ca0,1)2SO4 and Na6Ca(SO4)4 were obtained from a powder mixture of sodium sulfate Na2SO4 and calcium sulfate dihydrate CaSO42H2O, taken at a molar ratio CaSO42H2O/Na2SO4 = 1. The phase composition of the powder mixture after homogenization in a planetary mill in an acetone medium, in addition to the starting salts, also included hydrated sodium calcium sulfate Na4Ca(SO4)32H2O. When kept in water for 5 and 60 min the mass loss of ceramic sample fired at 700 °C was 15 and 75 % respectively. Ceramics in the Na2O–CaO–SO3 system in the form of granules or complex shapes obtained using 3D printing can be used as a removable (soluble or leachable) porogen and/or a prototype of a porous space with a given architecture when creating porous polymer or inorganic materials.