Table 1 Physicochemical properties and element concentrations of tailings and ores.

Paste pH

8.33

6.72

7.83

7.23

6.89

7.59

6.65

7.84

–

Paste EC (μs/cm)

650

253

1066

524

325

624

368

200

–

As (mg/kg)

2.84

3.16

5.37

3.20

22.61

9.42

4.25

3.13

30 (6.5 < pH ≤ 7.5)

25 (pH > 7.5)

Cu (mg/kg)

491.6

1062.5

47,260.7

5162.0

1940.8

5851.3

2758.1

115.9

100

Pb (mg/kg)

9.07

5.13

14.72

5.30

11.30

5.63

4.81

4.13

120 (6.5 < pH ≤ 7.5)

170 (pH > 7.5)

Zn (mg/kg)

189.10

49.09

70.70

33.76

22.03

71.06

26.18

75.91

250 (6.5 < pH ≤ 7.5)

300 (pH > 7.5)

Cd (mg/kg)

2.89

0.06

2.93

0.10

0.16

0.14

0.04

0.31

0.3 (6.5 < pH ≤ 7.5)

0.6 (pH > 7.5)

Cr (mg/kg)

65.65

10.25

12.88

5.29

9.61

13.93

17.96

12.33

200 (6.5 < pH ≤ 7.5)

250 (pH > 7.5)

Ni (mg/kg)

19.35

4.34

2.01

2.28

3.98

19.54

5.61

18.65

100 (6.5 < pH ≤ 7.5)

190 (pH > 7.5)

Mo (mg/kg)

14.58

3.09

25.09

13.81

134.02

52.78

19.60

0.36

–

Mn (mg/kg)

483.0

609.7

244.2

335.2

171.4

607.5

262.9

766.2

–

Fe (g/kg)

35.98

37.44

48.72

39.07

13.17

73.69

29.08

88.59

–

S (g/kg)

0.54

0.83

43.87

10.02

1.43

13.31

1.42

1.31

–