11
that the mineral structure of the manganese Cu-Ni-bearing
oxides was destroyed and reprecipitated as a barren manga-
nese oxide.
FLOWSHEET OPTIONS
The leach liquor compositions shown in Table 6 of ~4 g/L
Cu, 5 g/L Ni, 0.8 g/L Co, 8 g/L Mn, and 2.5 g/L Fe are
amenable for conventional metal recovery options:
• Excess acid can be neutralized via conventional lime-
stone neutralization. Other means of consuming the
excess acid (such as counter current leaching) should
be considered.
• Copper can be recovered selectively via either SX-EW
or sulphide precipitation.
• Impurities (Fe, Cr, Al, etc.) can be removed via pre-
cipitation (possibly in a twostage configuration)
using lime or limestone.
• Manganese can be recovered selectively via SX
(D2EHPA).
• Cobalt and nickel can be recovered together as an
MHP or MSP product, or separately via SX (Cyanex
272, Versatic 10).
• While final effluent treatment is dependent on the
metal recovery processes selected, it is expected to
include production of sodium or ammonium sul-
phate if SX is included.
Finally, it is worth pointing out that if a production
capacity of 60,000 t/a of nickel is selected, and manganese
extraction of 5% is assumed, this would lead to 225 kt/a of
HPMSM, or around 1.75 times the planned production
by E25. Considering the increased usage of manganese in
lithium-ion battery chemistries, this provides a more realis-
tic production scenario than processing all manganese into
HPMSM.
Valid concerns exist around the handling or final out-
come of the Mn-rich leach residue, as well as potential
waste products such as gypsum (produced by limestone
neutralization) and crystallized sodium or ammonium sul-
phate salts. However, many of these issues are no differ-
ent than those encountered in current black mass recycling
projects and other terrestrial mining operations (such as
lithium conversion plants).
CONCLUSIONS
Preliminary testwork has shown that selective recovery of
nickel (98%), copper (94%) and cobalt (92%) against
manganese (6–7%), iron (10%) and aluminum (10%)
is feasible using conventional high pressure acid leaching
(HPAL) technology. While HPAL processing of nodules
Feed HPAL Residue
30 20.2 34.9
61.1 40.8
18.7 24.3
0
10
20
30
40
50
60
70
80
90
100
Figure 7. Summary of exposure (Mass%) of Mn-(Cu,Ni) calculated for the Feed and HPAL
Leach Residue
Mass
(%
Mn-(Cu,Ni))
that the mineral structure of the manganese Cu-Ni-bearing
oxides was destroyed and reprecipitated as a barren manga-
nese oxide.
FLOWSHEET OPTIONS
The leach liquor compositions shown in Table 6 of ~4 g/L
Cu, 5 g/L Ni, 0.8 g/L Co, 8 g/L Mn, and 2.5 g/L Fe are
amenable for conventional metal recovery options:
• Excess acid can be neutralized via conventional lime-
stone neutralization. Other means of consuming the
excess acid (such as counter current leaching) should
be considered.
• Copper can be recovered selectively via either SX-EW
or sulphide precipitation.
• Impurities (Fe, Cr, Al, etc.) can be removed via pre-
cipitation (possibly in a twostage configuration)
using lime or limestone.
• Manganese can be recovered selectively via SX
(D2EHPA).
• Cobalt and nickel can be recovered together as an
MHP or MSP product, or separately via SX (Cyanex
272, Versatic 10).
• While final effluent treatment is dependent on the
metal recovery processes selected, it is expected to
include production of sodium or ammonium sul-
phate if SX is included.
Finally, it is worth pointing out that if a production
capacity of 60,000 t/a of nickel is selected, and manganese
extraction of 5% is assumed, this would lead to 225 kt/a of
HPMSM, or around 1.75 times the planned production
by E25. Considering the increased usage of manganese in
lithium-ion battery chemistries, this provides a more realis-
tic production scenario than processing all manganese into
HPMSM.
Valid concerns exist around the handling or final out-
come of the Mn-rich leach residue, as well as potential
waste products such as gypsum (produced by limestone
neutralization) and crystallized sodium or ammonium sul-
phate salts. However, many of these issues are no differ-
ent than those encountered in current black mass recycling
projects and other terrestrial mining operations (such as
lithium conversion plants).
CONCLUSIONS
Preliminary testwork has shown that selective recovery of
nickel (98%), copper (94%) and cobalt (92%) against
manganese (6–7%), iron (10%) and aluminum (10%)
is feasible using conventional high pressure acid leaching
(HPAL) technology. While HPAL processing of nodules
Feed HPAL Residue
30 20.2 34.9
61.1 40.8
18.7 24.3
0
10
20
30
40
50
60
70
80
90
100
Figure 7. Summary of exposure (Mass%) of Mn-(Cu,Ni) calculated for the Feed and HPAL
Leach Residue
Mass
(%
Mn-(Cu,Ni))