Sample No.

Longnan abrasion pH

Lonan exchange pH

Anyuan abrasion pH

Anyuan exchange pH

Dinan abrasion pH

Dinan exchange pH

1

5.47

4.34

6.13

4.3

5.7

4.5

2

5.35

4.33

6.14

4.32

6.18

4.49

3

5.5

4.33

6.18

4.28

5.76

4.48

4

5.74

4.39

5.92

4.43

5.72

4.72

5

5.67

4.39

5.93

4.39

5.69

4.75

6

5.68

4.43

6.24

4.37

5.71

4.74

Average

5.57 ± 0.13

4.37 ± 0.03

6.09 ± 0.11

4.35 ± 0.05

5.80 ± 0.13

4.61 ± 0.12