Thermal stabiliy of woolly erionite-K and considerations about the heat-induced behaviour of the erionite group
The thermal behavior of a woolly erionite-K sample (Lander County, NV, USA), chemical formula (Ca2.03 Na0.73 K2.52 Mg0.26)[Al8.22 Si27.78 O71.80 ]·35.94H2 O, was investigated in the 303–1173 K thermal range by in situ X-ray powder diffraction. Present data suggest a general thermally-induced volume contraction whose magnitude increases as(formula presented) ratio becomes smaller. An inverse correlation between(formula presented) ratio and Tdehydr is observed because higher(formula presented) ratio values are associated to lower dehydration temperatures.