3488 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
solution to mitigate the slime coating problem. However,
when dealing with more complex mineralogical composi-
tions, it becomes crucial to explore more effective solutions.
Table 4 presents the flotation results obtained by using
different dosages of hexametaphosphate (SHMP) and using
only NaOH for dispersion. The findings reveal that both
were not successful in reducing iron (Fe) content in the
tailings. The ionic force introduced into the medium by
the addition of SHMP was insufficient to keep the ultrafine
particles in suspension, hindering the achievement of opti-
mal selectivity in flotation.
The imperative for a more potent solution becomes
apparent when tackling ores with complex mineralogical
compositions. Ultrasound has been identified as a promising
solution worthy of further exploration in addressing this
complexity. The ultrasound exposure duration was a key
variable under evaluation, and the optimal time was deter-
mined to be 10 minutes. This duration resulted in the
highest iron (Fe) content in the concentrate, coupled with
the lowest Fe content in the tailings. The results are shown
Table 5.
The intensity of exposure and the percentage of solids
are two other important variables in the result. The first one
shows significant gains in the reduction of Fe in the tail-
ings even at low intensities as showed by Figure 1 and the
second shows that more diluted pulps have better results as
showed by Figure 2.
Table 4. Flotation results with different SHMP dosages
Without
Dispersion pH 10.5 SHMP 250g/t SHMP 500g/t SHMP 750g/t
Fe Feed, %51,1 51,1 51,1 51,1 51,1
Fe Concentrate, %57,4 56,3 56,3 57,0 56,6
Fe Tailing, %29,2 31,9 33,0 28,9 27,6
Mass Recovery, %77,7 78,7 77,7 79,2 81,2
Metal Recovery, %87,3 86,7 85,6 88,3 89,9
Table 5. Flotation results with different ultrasound residence time
0 min 5 min 10 min 15 min
Fe Feed, %51,1 51,1 51,1 51,1
Fe Concentrate, %57,4 56,6 57,4 55,4
Fe Tailing, %29,2 24,5 22,3 24,1
Mass Recovery, %77,7 82,9 82,1 86,5
Metal Recovery, %87,3 91,8 92,2 93,6
y =0.0028x2 -0.2588x +27.902
R² =0.8692
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
0 25 50 75 100 125
Ultrasound Intensity (%)
Fe Tailing
y =-0.0021x2 +0.2101x +88.515
R² =0.8261
86.0
87.0
88.0
89.0
90.0
91.0
92.0
93.0
94.0
95.0
0 25 50 75 100 125
Ultrasound Intensity (%)
Metal Recovery
Figure 1. Flotation results with different ultrasound intensity
Fe
Tailing
(%)
Fe
Tailing
(%)
solution to mitigate the slime coating problem. However,
when dealing with more complex mineralogical composi-
tions, it becomes crucial to explore more effective solutions.
Table 4 presents the flotation results obtained by using
different dosages of hexametaphosphate (SHMP) and using
only NaOH for dispersion. The findings reveal that both
were not successful in reducing iron (Fe) content in the
tailings. The ionic force introduced into the medium by
the addition of SHMP was insufficient to keep the ultrafine
particles in suspension, hindering the achievement of opti-
mal selectivity in flotation.
The imperative for a more potent solution becomes
apparent when tackling ores with complex mineralogical
compositions. Ultrasound has been identified as a promising
solution worthy of further exploration in addressing this
complexity. The ultrasound exposure duration was a key
variable under evaluation, and the optimal time was deter-
mined to be 10 minutes. This duration resulted in the
highest iron (Fe) content in the concentrate, coupled with
the lowest Fe content in the tailings. The results are shown
Table 5.
The intensity of exposure and the percentage of solids
are two other important variables in the result. The first one
shows significant gains in the reduction of Fe in the tail-
ings even at low intensities as showed by Figure 1 and the
second shows that more diluted pulps have better results as
showed by Figure 2.
Table 4. Flotation results with different SHMP dosages
Without
Dispersion pH 10.5 SHMP 250g/t SHMP 500g/t SHMP 750g/t
Fe Feed, %51,1 51,1 51,1 51,1 51,1
Fe Concentrate, %57,4 56,3 56,3 57,0 56,6
Fe Tailing, %29,2 31,9 33,0 28,9 27,6
Mass Recovery, %77,7 78,7 77,7 79,2 81,2
Metal Recovery, %87,3 86,7 85,6 88,3 89,9
Table 5. Flotation results with different ultrasound residence time
0 min 5 min 10 min 15 min
Fe Feed, %51,1 51,1 51,1 51,1
Fe Concentrate, %57,4 56,6 57,4 55,4
Fe Tailing, %29,2 24,5 22,3 24,1
Mass Recovery, %77,7 82,9 82,1 86,5
Metal Recovery, %87,3 91,8 92,2 93,6
y =0.0028x2 -0.2588x +27.902
R² =0.8692
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
0 25 50 75 100 125
Ultrasound Intensity (%)
Fe Tailing
y =-0.0021x2 +0.2101x +88.515
R² =0.8261
86.0
87.0
88.0
89.0
90.0
91.0
92.0
93.0
94.0
95.0
0 25 50 75 100 125
Ultrasound Intensity (%)
Metal Recovery
Figure 1. Flotation results with different ultrasound intensity
Fe
Tailing
(%)
Fe
Tailing
(%)