Thermal decompositions of ammonium and potassium alums

Article abstract of DOI:10.1007/BF01913929

Simultaneous TG, DTG and DTA studies of NH₄Al(SO₄)₂.12H₂O and KAl(SO₄)₂.12H₂O under nonisothermal conditions were performed with a derivatograph, over the temperature range from 293 K to 1473 K under air and argon atmospheres. Appropriate chemical reactions were attributed to the thermal effects, with consideration of the results of X-ray diffraction and microscopic analyses. From the recorded curves, the activation energies E_a were calculated for all steps of the thermal decomposition.