Ore Type

Reductant

Maximum Ni

Recovery (%)

Temp. of

Maximum Ni Recovery (˚C)

Ni Grade At

Maximum (%)

Optimum

Observed

Reference

Limonitic

CO/CO₂

̴100

550

N/A

yes

[29]

Limonitic

H₂/H₂O

̴100

550

N/A

N/A

[29]

Limonitic

CO₂/H₂

̴100

700 - 800

60

yes

[30]

Saprolitic

CO/CO₂

82

700

N/A

yes

[29]

Saprolitic

CO/CO₂

78

900

N/A

yes

[29]

Saprolitic

H₂/H₂O

85

850

N/A

N/A

[29]

Saprolitic

CO/CO₂

85

740

41

yes

[31]

Saprolitic

CO

75

800

N/A

yes

[32]

Saprolitic

C (anthracite)

84

1000

N/A

no

[32]