XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2777
and final recovery would be around 350 Hz, and at this
frequency (350 Hz), an increase in the sound amplitude
would increase the flotation rate and final recovery (Ng
et al., 2020a). No flotation tests were done above 125 dB
owing to workplace health and safety concerns.
Figure 4 shows the improvement of flotation recovery
at different size fractions, especially the coarse one (Yang et
al., 2023). The results indicate that at particle size coarser
than 20 µm, final flotation recoveries were improved by
applying acoustic sound. Especially, for relatively coarse
particles (150–212 µm particles), the flotation recovery
increased 0 to 25.1 per cent. Note that in this work, use
of sound had little improvement of the flotation recovery
for ultrafine particles (below 20 µm), probably because of
the already high froth stability and flotation recovery in the
blank test.
Figure 5a shows in coking coal flotation it is possible to
use acoustic sound to cut the frother dosage by 1/3 (from
a typical dosage of 15 ppm to 10 ppm) while maintaining
the flotation recovery the same in a flotation column (Ng et
al., 2021). Figure 5b shows that cleaner coal product can be
achieved using sound while keeping the yield (mass recov-
ery) the same (Ng et al., 2021).
Rougher flotation tests were conducted for a real cop-
per ore with the valuables being copper sulphides, using the
experimental setup shown in Figure 2a. Figure 6 shows that
use of acoustic sound (at the same condition except turn-
ing on or off the sound) found an increase in mass recovery
010 59 09 58 015 110 115 210 215 310
90
91
92
93
94
95
96
97
98
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0.55
85 90 95 100 105 110 115 120 125 130
Sound amplitude (dB)
b)
Blank test
Blank test
2 00 2 50 3 00 3 50 4 00 4 50 5 00 5 50
90
91
92
93
94
95
96
97
98
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
0.55
200 250 300 350 400 450 500 550
Sound frequency (Hz)
a)
Blank test
Blank test
Source: Ng et al., 2020a.
Figure 3. Effects of sound frequency and amplitude on quartz flotation rate constant (k) and final recovery (R
max ).An
underwater speaker was used within a mechanical flotation cell (see Figure 2a)
Source: Yang et al. 2023a.
Figure 4. Size-by-size recovery of quartz flotation with and without sound (at 375 Hz). An
underwater speaker was used within a mechanical flotation cell (see Figure 2a)
Rmax(%) K(min-1) Rmax(%) K(min-1)
and final recovery would be around 350 Hz, and at this
frequency (350 Hz), an increase in the sound amplitude
would increase the flotation rate and final recovery (Ng
et al., 2020a). No flotation tests were done above 125 dB
owing to workplace health and safety concerns.
Figure 4 shows the improvement of flotation recovery
at different size fractions, especially the coarse one (Yang et
al., 2023). The results indicate that at particle size coarser
than 20 µm, final flotation recoveries were improved by
applying acoustic sound. Especially, for relatively coarse
particles (150–212 µm particles), the flotation recovery
increased 0 to 25.1 per cent. Note that in this work, use
of sound had little improvement of the flotation recovery
for ultrafine particles (below 20 µm), probably because of
the already high froth stability and flotation recovery in the
blank test.
Figure 5a shows in coking coal flotation it is possible to
use acoustic sound to cut the frother dosage by 1/3 (from
a typical dosage of 15 ppm to 10 ppm) while maintaining
the flotation recovery the same in a flotation column (Ng et
al., 2021). Figure 5b shows that cleaner coal product can be
achieved using sound while keeping the yield (mass recov-
ery) the same (Ng et al., 2021).
Rougher flotation tests were conducted for a real cop-
per ore with the valuables being copper sulphides, using the
experimental setup shown in Figure 2a. Figure 6 shows that
use of acoustic sound (at the same condition except turn-
ing on or off the sound) found an increase in mass recovery
010 59 09 58 015 110 115 210 215 310
90
91
92
93
94
95
96
97
98
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0.55
85 90 95 100 105 110 115 120 125 130
Sound amplitude (dB)
b)
Blank test
Blank test
2 00 2 50 3 00 3 50 4 00 4 50 5 00 5 50
90
91
92
93
94
95
96
97
98
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
0.55
200 250 300 350 400 450 500 550
Sound frequency (Hz)
a)
Blank test
Blank test
Source: Ng et al., 2020a.
Figure 3. Effects of sound frequency and amplitude on quartz flotation rate constant (k) and final recovery (R
max ).An
underwater speaker was used within a mechanical flotation cell (see Figure 2a)
Source: Yang et al. 2023a.
Figure 4. Size-by-size recovery of quartz flotation with and without sound (at 375 Hz). An
underwater speaker was used within a mechanical flotation cell (see Figure 2a)
Rmax(%) K(min-1) Rmax(%) K(min-1)
