XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3225
The optimal process outcome is such where every mate-
rial is separated in a useful form. In this work, the focus
was only on NMC and graphite (Gr) recovery and grade
in the final Tailings 2 and Concentrate 2 streams respec-
tively. This implies the removal of other materials in other
output streams before the final stage. With these objectives
in mind, the data on the mass flow and grade of NMC
and Gr in the final flotation output streams of all simu-
lated process variations was analysed. Additional informa-
tion was obtained by analysing the flow of other materials
in the remaining streams. The statistical spreads of all pos-
sible outcomes, data bias and averages were used to guide
decision making on how the process might be modified to
improve process outcomes towards the desired objectives.
The average outcomes and biases illustrate the general ten-
dencies of the process, but the extreme of all possible out-
comes point towards the parameters sets that most improve
materials flow.
RESULTS
Fristly, data analysis of the 10,000 process variations for
the postulated model process was performed. Figure 4 illus-
trates the spread of possible outcomes for materials flow
of Gr in the concentrate stream and NMC in the tailings
stream, reflecting our ideal separation target. Grade and
mass flow data were analysed, and the recovered mass was
also normalized by the input mass content to clarify the
fraction of mass recovery.
A broad distribution of 0 -31.7 t/h (0 to 74.2% of
the input feed) in recovered NMC mass in the tailings was
observed, displayed in Figure 4a). The distribution peaks
near the minimum, revealing that most parameter varia-
tions still result in low mass recovery, with an average of
4 t/h (9.4%). Nevertheless, the long tail suggests that by
adjusting parameters, this process could recover up to
89% of the total input NMC mass. The grade of recovered
NMC in Figure 4b) exhibits variation in the wide range of
2.5% -62.5%. The purity outcomes are also heavily biased
towards the lower range, but the long tail indicates that fea-
sible parameter combinations would increase the grade of
NMC significantly past its initial grade of 23.7% in the
input feed.
The recovered mass distribution of graphite in the con-
centrate is presented in Figure 4c). The mass flow range was
broad, with a high maximum of 86.3% recovered mate-
rial. Nevertheless, the long tail of the distribution to 0%
presents a warning to avoid process parameters that lead to
minimal graphite recovery. Figure 4d) illustrates the grade
distributions of graphite in concentrate with a very narrow
distribution of almost 100% of graphite purity. A detailed
comparison of NMC and graphite performance markers
for both processes is presented in Table 2.
The statistical analysis above revealed much informa-
tion about the capabilities of the postulated process. While
the recovery of graphite mass was generally very good at
77.4% on average, poor outcomes were also possible, and
these process parameters must be avoided i.e short (10
min) residence time in flotation cells and high (0.1 T)
magnetic field in the magnetic separator. Graphite 99.4%
average purity in concentrate was difficult to improve on.
The average grade of NMC in Tailings 2, on the other hand,
is considered low at 8.8%. Similarly, this process could
Figure 4. Statistical distributions of 10,000 process outputs for the materials flow of NMC and graphite:
a) NMC mass flow in tailings, b) NMC grade in tailings 2, c) graphite mass flow in concentrate 2, d) graphite grade
in concentrate 2. The red dashed line indicates the input feed value, and the black full line illustrates the mean of the
distributions
The optimal process outcome is such where every mate-
rial is separated in a useful form. In this work, the focus
was only on NMC and graphite (Gr) recovery and grade
in the final Tailings 2 and Concentrate 2 streams respec-
tively. This implies the removal of other materials in other
output streams before the final stage. With these objectives
in mind, the data on the mass flow and grade of NMC
and Gr in the final flotation output streams of all simu-
lated process variations was analysed. Additional informa-
tion was obtained by analysing the flow of other materials
in the remaining streams. The statistical spreads of all pos-
sible outcomes, data bias and averages were used to guide
decision making on how the process might be modified to
improve process outcomes towards the desired objectives.
The average outcomes and biases illustrate the general ten-
dencies of the process, but the extreme of all possible out-
comes point towards the parameters sets that most improve
materials flow.
RESULTS
Fristly, data analysis of the 10,000 process variations for
the postulated model process was performed. Figure 4 illus-
trates the spread of possible outcomes for materials flow
of Gr in the concentrate stream and NMC in the tailings
stream, reflecting our ideal separation target. Grade and
mass flow data were analysed, and the recovered mass was
also normalized by the input mass content to clarify the
fraction of mass recovery.
A broad distribution of 0 -31.7 t/h (0 to 74.2% of
the input feed) in recovered NMC mass in the tailings was
observed, displayed in Figure 4a). The distribution peaks
near the minimum, revealing that most parameter varia-
tions still result in low mass recovery, with an average of
4 t/h (9.4%). Nevertheless, the long tail suggests that by
adjusting parameters, this process could recover up to
89% of the total input NMC mass. The grade of recovered
NMC in Figure 4b) exhibits variation in the wide range of
2.5% -62.5%. The purity outcomes are also heavily biased
towards the lower range, but the long tail indicates that fea-
sible parameter combinations would increase the grade of
NMC significantly past its initial grade of 23.7% in the
input feed.
The recovered mass distribution of graphite in the con-
centrate is presented in Figure 4c). The mass flow range was
broad, with a high maximum of 86.3% recovered mate-
rial. Nevertheless, the long tail of the distribution to 0%
presents a warning to avoid process parameters that lead to
minimal graphite recovery. Figure 4d) illustrates the grade
distributions of graphite in concentrate with a very narrow
distribution of almost 100% of graphite purity. A detailed
comparison of NMC and graphite performance markers
for both processes is presented in Table 2.
The statistical analysis above revealed much informa-
tion about the capabilities of the postulated process. While
the recovery of graphite mass was generally very good at
77.4% on average, poor outcomes were also possible, and
these process parameters must be avoided i.e short (10
min) residence time in flotation cells and high (0.1 T)
magnetic field in the magnetic separator. Graphite 99.4%
average purity in concentrate was difficult to improve on.
The average grade of NMC in Tailings 2, on the other hand,
is considered low at 8.8%. Similarly, this process could
Figure 4. Statistical distributions of 10,000 process outputs for the materials flow of NMC and graphite:
a) NMC mass flow in tailings, b) NMC grade in tailings 2, c) graphite mass flow in concentrate 2, d) graphite grade
in concentrate 2. The red dashed line indicates the input feed value, and the black full line illustrates the mean of the
distributions