TG/DTA/MS Study of the thermal decomposition of FeSO₄·6H₂O

International audienceThe thermal decomposition of FeSO4•6H2O was studied by mass spectroscopy coupled with DTA/TG thermal analysis under inert atmosphere. On the ground of TG measurements, the mechanism of decomposition of FeSO4•6H2O is: i) three dehydration steps FeSO4•6H2O FeSO4•4H2O+2H2O FeSO4•4H2O FeSO4•H2O+3H2O FeSO4•H2O FeSO4+H2O ii) two decomposition steps 6FeSO4 Fe2(SO4)3+2Fe2O3+2SO2 Fe2(SO4)3 Fe2O3+3SO2+3/2O2 The intermediate compound was identified as Fe2(SO4)3 and the final product as the hematite Fe2O3