The preparation of sulfoaluminate cementitious materials (SCM) is a promising way to massively utilize solid wastes. Iron phases are significant in SCM system but the thermodynamic data of some key minerals

such as 6CaO·Al

2

O

3

·2Fe

2

O

3

(C

6

AF

2

) and 6CaO·2Al

2

O

3

·Fe

2

O

3

(C

6

A

2

F)

are missing

which greatly hinders the SCM optimization in a theoretical way. This work

for the first time

calculated the standard formation enthalpy

Gibbs free energy of formation

entropy and molar heat capacity for C

6

AF

2

and C

6

A

2

F and lowered the errors to the least with the reference of C

4

AF data in the literature. By building the function diagram of Gibbs free energy changes with temperature for the basic iron phase formation reactions with the obtained thermodynamic data

it is proved that the formation likeliness of C

6

AF

2

is higher than that of C

6

A

2

F

as is accordant to the literatures and verifies the correctness of obtained data. This work provides a good theoretica

l foundation to optimize SCM mineral system and to study relevant mechanism deeply.