O/R ratio

Leaching efficiency, %

Nb

Ta

REE

Ti

Zr

1/1

72.1

70.5

78

61.5

5

1/2

95.0

93.7

96

75

10

1/3

90.2

88

91

71

10

1/4

88.8

82

87

68.2

9.5