8
ion selectivity for one such commercially available resin. It
can be seen the Cu, Fe3+, Ni, and Zn will load with Co. Cu
and Fe3+ are handled via a iron cementation pretreatment
step. The Zn and Ni are removed by IX treatment of the
eluate.
Feed to the pilot plant is raw raffinate solution, derived
from the Mantoverde commercial heap operation, which
is spiked with cobalt sulphate to simulate the modelled
concentration of cobalt reporting to the heap leach PLS in
the future. The pilot circuit consisted of an iron cementa-
tion stage followed by filtration of the precipitate. Filtrates
are pH adjusted and passed through a carrousel style con-
tinuous countercurrent ion exchange unit (CCIX), devel-
oped by Puritech, loaded with BPA resin (Rochette &De
Busscher, 2016). Loaded elements, including cobalt, nickel
and residual iron, are stripped from the resin in stages to
produce a cobalt rich PLS, nickel rich PLS and raffinate.
Key variables tested in the program included:
• Feed grade with cobalt, nickel, total iron and ferrous
to ferric ratio adjusted
• Iron powder dosage
• pH of CCIX feed
• Cementation residence time and ORP target
• Feed flow and strip flow rates
• Acid concentration in strip
• PLS recycle
• CCIX indexing time
CCIX eluate reports to a solution purification step,
where residual Zn, Fe3+, Al, and other impurities are
removed. The purified cobalt sulfate solution then reports
to a hydroxide precipitation step. The final cobalt hydrox-
ide precipitate is between 40% and 45% Cobalt.
Process Modeling
A dynamic process model (Figure 10) was built using
METSIM ® that included all unit operations associated
with the MV operation, as well as the past and forecasted
ore tons and grade schedule for ore stacked on the heap
leach pads. From this base-case model, two proposed sce-
narios were developed: i) the conversion to a bioleach via
Figure 6. Ion selectivity for a BPA resin (Dupont, 2020)
Figure 7. CCIX pilot plant provided by Puritech
Figure 8. pilot plant product solutions for various streams
ion selectivity for one such commercially available resin. It
can be seen the Cu, Fe3+, Ni, and Zn will load with Co. Cu
and Fe3+ are handled via a iron cementation pretreatment
step. The Zn and Ni are removed by IX treatment of the
eluate.
Feed to the pilot plant is raw raffinate solution, derived
from the Mantoverde commercial heap operation, which
is spiked with cobalt sulphate to simulate the modelled
concentration of cobalt reporting to the heap leach PLS in
the future. The pilot circuit consisted of an iron cementa-
tion stage followed by filtration of the precipitate. Filtrates
are pH adjusted and passed through a carrousel style con-
tinuous countercurrent ion exchange unit (CCIX), devel-
oped by Puritech, loaded with BPA resin (Rochette &De
Busscher, 2016). Loaded elements, including cobalt, nickel
and residual iron, are stripped from the resin in stages to
produce a cobalt rich PLS, nickel rich PLS and raffinate.
Key variables tested in the program included:
• Feed grade with cobalt, nickel, total iron and ferrous
to ferric ratio adjusted
• Iron powder dosage
• pH of CCIX feed
• Cementation residence time and ORP target
• Feed flow and strip flow rates
• Acid concentration in strip
• PLS recycle
• CCIX indexing time
CCIX eluate reports to a solution purification step,
where residual Zn, Fe3+, Al, and other impurities are
removed. The purified cobalt sulfate solution then reports
to a hydroxide precipitation step. The final cobalt hydrox-
ide precipitate is between 40% and 45% Cobalt.
Process Modeling
A dynamic process model (Figure 10) was built using
METSIM ® that included all unit operations associated
with the MV operation, as well as the past and forecasted
ore tons and grade schedule for ore stacked on the heap
leach pads. From this base-case model, two proposed sce-
narios were developed: i) the conversion to a bioleach via
Figure 6. Ion selectivity for a BPA resin (Dupont, 2020)
Figure 7. CCIX pilot plant provided by Puritech
Figure 8. pilot plant product solutions for various streams