Thermal decomposition of illite

the effect of heat treatment on illite in air at temperatures ranging from 750 to 1150 °c was studied using the m？ssbauer effect in 57fe. the dependence of the m？ssbauer parameters and relative percentage of the radiation absorption area was measured as a function of the firing temperature. the onset of thermal structural decomposition occurred at 800 °c. with rising temperature, the formation of hematite (fe2o3) increased at the expense of the silicate mineral.