326 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
While not demonstrated by BGRIMM, this hydroxide
could then be converted to other cobalt products, possibly
as cobalt sulfide or even crystallized as cobalt sulfate.
Note that no REEs were detected in leachates from the
Cuprion Sulfate leach tests. Analysis of the leach residues
confirmed that the REEs remained in the final residue.
BGRIMM encountered issues which would also be
seen in the subsequent test program at ALS. One was that
the filtration of the leach slurry had to be conducted in a
manner that prevented precipitation of extracted metals in
the filter cake, which would result in lower reported extrac-
tions than were achieved. Another was a near universal dif-
ficulty in analyzing ammonia-based solutions with ICP or
AA systems. Specific sample dilution methods can mitigate
the ammonia problem.
All the extractions in the BGRIMM (and later ALS)
tests were calculated by comparing head and residue assays.
The addition of cobalt, copper, nickel, and manganese to
the feed leach solution made calculations based on preg-
nant liquor and residue concentrations difficult. In the case
of copper, the feed leach solution contained more copper
than could be leached from the nodules, which made mass
balances on copper particularly difficult.
Based upon the OML-BGRIMM bench test program
of the Cuprion Sulfate process, a proposed flowsheet pro-
duces the following saleable products:
Figure 4. Modified Cuprion (Cuprion sulfate) process flowv
While not demonstrated by BGRIMM, this hydroxide
could then be converted to other cobalt products, possibly
as cobalt sulfide or even crystallized as cobalt sulfate.
Note that no REEs were detected in leachates from the
Cuprion Sulfate leach tests. Analysis of the leach residues
confirmed that the REEs remained in the final residue.
BGRIMM encountered issues which would also be
seen in the subsequent test program at ALS. One was that
the filtration of the leach slurry had to be conducted in a
manner that prevented precipitation of extracted metals in
the filter cake, which would result in lower reported extrac-
tions than were achieved. Another was a near universal dif-
ficulty in analyzing ammonia-based solutions with ICP or
AA systems. Specific sample dilution methods can mitigate
the ammonia problem.
All the extractions in the BGRIMM (and later ALS)
tests were calculated by comparing head and residue assays.
The addition of cobalt, copper, nickel, and manganese to
the feed leach solution made calculations based on preg-
nant liquor and residue concentrations difficult. In the case
of copper, the feed leach solution contained more copper
than could be leached from the nodules, which made mass
balances on copper particularly difficult.
Based upon the OML-BGRIMM bench test program
of the Cuprion Sulfate process, a proposed flowsheet pro-
duces the following saleable products:
Figure 4. Modified Cuprion (Cuprion sulfate) process flowv