Ceramics-Silikáty 58 (1) 21-27 (2014)

ALPHA PLASTER PRODUCED BY PRESSURELESS METHOD OF DEHYDRATION IN SALT SOLUTION

This study deals with development of production procedure of alpha plaster by the method of dehydration in salt solution, which is focused on the use chloride dusts as dehydration agent. For the dehydration of gypsum testing solution containing NaCl and KCl were used. Potassium chloride alone is unusable for dehydration, because simultaneously with the dehydration process the competitive process of gorgeyite creation occurs at a much higher reaction velocity. Sodium ions decrease the reaction velocity of goregyite formation. The mass concentration of 20 % dehydration solution containing 75 % of potassium chloride and 25 % of sodium chloride is optimal for mixed dehydration solution.

Keywords: Alpha gypsum, Pressure less method, Salt solution