Table 1 Chemical composition of reactant and product analyzed by energy dispersive spectroscopy (EDS)

Oxides (%)

SO₃

68.95

69.10

24.08

24.28

32.90

33.01

31.90

33.66

FeO

31.05

30.91

1.42

0.63

–

–

–

–

PbO

–

–

74.50

75.09

–

–

–

–

BaO

–

–

–

–

67.10

66.99

68.10

66.34

wt.(%)

O

48.25

48.47

20.09

20.08

26.72

26.78

26.23

27.10

S

27.61

27.58

9.64

9.72

13.18

13.22

12.77

13.48

Fe

24.14

23.95

1.10

0.49

–

–

–

–

Pb

–

–

69.16

69.71

–

–

–

–

Ba

–

–

–

–

60.10

60.00

61.00

59.42

at. (%)

O

69.99

70.15

65.75

65.93

66.31

66.34

66.05

66.51

S

19.99

19.92

15.75

15.93

16.31

16.34

16.05

16.51

Fe

10.03

9.93

1.03

0.46

–

–

–

–

Pb

–

–

17.47

17.68

–

–

–

–

Ba

–

–

–

–

17.37

17.31

17.90

16.99

a.p.f.u. based on 24 oxygen atoms

S

6.85

6.82

5.75

5.80

5.90

5.91

5.83

5.96

Fe

3.44

3.40

0.38

0.17

–

–

–

–

Pb

–

–

6.38

6.43

–

–

–

–

Ba

–

–

–

–

6.29

6.26

6.50

6.13

Cation sum

10.29

10.22

12.50

12.40

12.19

12.18

12.33

12.09