Temperature treatment (˚C)

Loi (%)

Colour of sample

105 (Uncalcined GFESs)

0.98 ± 0.05

LB

700

12.93 ± 0.67

DG

800

46.58 ± 0.15

LG

900

47.65 ± 0.01

W

1000

47.73 ± 0.19

W

1100

48.48 ± 0.24

W