XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1879
The relative concentrations of the major and minor miner-
als in the sample are shown in Table 4. The distribution
of bytownite, magnetite, and calcite corresponds with
high concentrations of Mg, Fe, and Ca observed with the
ICP-OES.
The particle size distribution is presented in Figure.
3 (a), and it indicated that 80% of the particles in the
ground sample were below 74.65 and 36.79 microns after
milling for 5 and 10 minutes, respectively. Similarly, more
than 80% of the concentration of the valuable metals were
hosted in particles below 75 microns, as shown in Figure. 3
(b). The analysis shows that the valuable metals are present
in the fine fractions and particle size could influence leach-
ing recoveries.
The SEM micrograph and EDS images of the ground
precursor for the leaching experiments are displayed in
Figures. 4 and 5, respectively. The particle morphology
indicates that the particles are irregularly shaped and of
different sizes. The results of the EDS analysis (Figure. A1)
show the occurrence of mainly Fe at 33.5 wt.%, Ni at 32.6
wt.% and sulphur (S) at 34.0 wt.%, which indicates the
presence of fine and coarse liberated pentlandite grains.
Oxygen (O) was spotted in spectrum 19 at 2.3 wt.%.
The EDS map shows the association of Mg and Ca with
the pentlandite locked inside the silicates. The SEM-EDS
analysis predominantly highlights the sulfidic nature of the
rougher flotation tailings.
Response Surface Model and Statistical Evaluation
The CCD experimental design leaching responses are
shown in Table 5. A statistical relationship between the
leaching parameters and %recoveries was established with
the help of the RSM and CCD. This relationship was rep-
resented by five polynomial quadratic equations for Ni
(Eq. 2) and Cu (Eq. 3). The influence of the linear, two-
way, and square interactions between the responses and
0.8
1.3
1.8
2.3
2.8
3.3
3.8
10 15 20 25 30 35 40 45 50 55 60 65 70 75 80
2 Theta (°)
Bytownite
Calcite
Dolomite
Magnetite
Olivine
Pyrrhotite
Quartz
Metaschoepite
Pentlandite
Chalcopyrite
Figure 2. The XRD pattern of the rougher tailings
Table 4. The major and minor minerals obtained from the XRD
Major Minerals Relative Concentration (%)Minor Minerals Relative Concentration (%)
Bytownite 34.6 Metaschoepite 4.4
Calcite 6.2 Pentlandite 2.3
Dolomite 5.2 Chalcopyrite 1.8
Magnetite 6.4 Safflorite 2.0
Olivine 17.9 Perovskite 2.9
Pyrrhotite 8.7
Quartz 7.6
Intensity
(a.u)
The relative concentrations of the major and minor miner-
als in the sample are shown in Table 4. The distribution
of bytownite, magnetite, and calcite corresponds with
high concentrations of Mg, Fe, and Ca observed with the
ICP-OES.
The particle size distribution is presented in Figure.
3 (a), and it indicated that 80% of the particles in the
ground sample were below 74.65 and 36.79 microns after
milling for 5 and 10 minutes, respectively. Similarly, more
than 80% of the concentration of the valuable metals were
hosted in particles below 75 microns, as shown in Figure. 3
(b). The analysis shows that the valuable metals are present
in the fine fractions and particle size could influence leach-
ing recoveries.
The SEM micrograph and EDS images of the ground
precursor for the leaching experiments are displayed in
Figures. 4 and 5, respectively. The particle morphology
indicates that the particles are irregularly shaped and of
different sizes. The results of the EDS analysis (Figure. A1)
show the occurrence of mainly Fe at 33.5 wt.%, Ni at 32.6
wt.% and sulphur (S) at 34.0 wt.%, which indicates the
presence of fine and coarse liberated pentlandite grains.
Oxygen (O) was spotted in spectrum 19 at 2.3 wt.%.
The EDS map shows the association of Mg and Ca with
the pentlandite locked inside the silicates. The SEM-EDS
analysis predominantly highlights the sulfidic nature of the
rougher flotation tailings.
Response Surface Model and Statistical Evaluation
The CCD experimental design leaching responses are
shown in Table 5. A statistical relationship between the
leaching parameters and %recoveries was established with
the help of the RSM and CCD. This relationship was rep-
resented by five polynomial quadratic equations for Ni
(Eq. 2) and Cu (Eq. 3). The influence of the linear, two-
way, and square interactions between the responses and
0.8
1.3
1.8
2.3
2.8
3.3
3.8
10 15 20 25 30 35 40 45 50 55 60 65 70 75 80
2 Theta (°)
Bytownite
Calcite
Dolomite
Magnetite
Olivine
Pyrrhotite
Quartz
Metaschoepite
Pentlandite
Chalcopyrite
Figure 2. The XRD pattern of the rougher tailings
Table 4. The major and minor minerals obtained from the XRD
Major Minerals Relative Concentration (%)Minor Minerals Relative Concentration (%)
Bytownite 34.6 Metaschoepite 4.4
Calcite 6.2 Pentlandite 2.3
Dolomite 5.2 Chalcopyrite 1.8
Magnetite 6.4 Safflorite 2.0
Olivine 17.9 Perovskite 2.9
Pyrrhotite 8.7
Quartz 7.6
Intensity
(a.u)