XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 245
and 3.46 kWh/t. For the tests with high-voltage electrical
impulses, a total of 70 kg of material were tested for each
condition.
The PSD from the initial material and material after
the tests with electrical impulses was determined and is pre-
sented in Figure 19. The initial material is the coarsest and
most of the samples follow the same trend, however, small
differences are identifiable. The material treated with the
electrical impulses shows a slight deviation of the trend for
some of the samples.
The test conditions and results of each of the tests are
summarized in Table 7.
After the milling tests, the resulting PSDs were evalu-
ated. The results can be observed in Figure 20.
SUMMARY AND CONCLUSIONS
A continuously working system for the pretreatment of
materials with high-voltage electrical impulses was built
and commissioned at the facilities of the IART /TUBAF.
The machine allows the treatment of materials in a wide
range of particle sizes, between 1 to 22 mm. It offers the
possibility of widely varying parameters such as impulse
energy and frequency.
Preferential liberation of mica after treatment with
high-voltage electrical impulse treatment was measured.
Although the largest liberation was determined on the
samples treated with higher energy inputs (5.25 and
8.75 kWh/t), the sample treated with only 1.18 kWh/t
resulted in a 60% liberation degree of the biotite phase.
Differences in the liberation behaviour of biotite and mus-
covite were identified. These are presumably related to the
origin of these micas. The potential for the liberation of
commercially relevant lithium bearing micas is yet to be
investigated.
The use of the high-voltage electrical impulses as a
pre-treatment method, hence introducing cracks in the
microstructure and reducing the energy needed for further
mechanical treatment, was measured by comparative tests
between raw material and material exposed to the high-
voltage electrical impulses. The difference in the milling
energy was up to 20% in both materials, granodiorite and
the scheelite ore.
0 1 2 3 4 5 6 7 8
0
10
20
30
40
50
60
70
80
90
100
x, mm
Raw Material 2
140J-3Hz-40% EIT +MT2
140J-3Hz-60% EIT +MT2
140J-3Hz-80% EIT +MT2
140J-10Hz-40% EIT +MT2
140J-10Hz-60% EIT +MT2
140J-10Hz-80% EIT +MT2
280J-3Hz-40% EIT +MT2
280J-3Hz-60% EIT +MT2
280J-3Hz-80% EIT +MT2
280J-10Hz-40% EIT +MT2
280J-10Hz-60% EIT +MT2
280J-10Hz-80% EIT +MT2
PSD after EI-Treatment and Milling Tests
Scheelite ore
Figure 20. PSD of material treated with (Samples EIT+MT) and without high-voltage electrical impulse
treatment (Raw Material) after the milling tests at 20 m/s
Q3 ,
%
and 3.46 kWh/t. For the tests with high-voltage electrical
impulses, a total of 70 kg of material were tested for each
condition.
The PSD from the initial material and material after
the tests with electrical impulses was determined and is pre-
sented in Figure 19. The initial material is the coarsest and
most of the samples follow the same trend, however, small
differences are identifiable. The material treated with the
electrical impulses shows a slight deviation of the trend for
some of the samples.
The test conditions and results of each of the tests are
summarized in Table 7.
After the milling tests, the resulting PSDs were evalu-
ated. The results can be observed in Figure 20.
SUMMARY AND CONCLUSIONS
A continuously working system for the pretreatment of
materials with high-voltage electrical impulses was built
and commissioned at the facilities of the IART /TUBAF.
The machine allows the treatment of materials in a wide
range of particle sizes, between 1 to 22 mm. It offers the
possibility of widely varying parameters such as impulse
energy and frequency.
Preferential liberation of mica after treatment with
high-voltage electrical impulse treatment was measured.
Although the largest liberation was determined on the
samples treated with higher energy inputs (5.25 and
8.75 kWh/t), the sample treated with only 1.18 kWh/t
resulted in a 60% liberation degree of the biotite phase.
Differences in the liberation behaviour of biotite and mus-
covite were identified. These are presumably related to the
origin of these micas. The potential for the liberation of
commercially relevant lithium bearing micas is yet to be
investigated.
The use of the high-voltage electrical impulses as a
pre-treatment method, hence introducing cracks in the
microstructure and reducing the energy needed for further
mechanical treatment, was measured by comparative tests
between raw material and material exposed to the high-
voltage electrical impulses. The difference in the milling
energy was up to 20% in both materials, granodiorite and
the scheelite ore.
0 1 2 3 4 5 6 7 8
0
10
20
30
40
50
60
70
80
90
100
x, mm
Raw Material 2
140J-3Hz-40% EIT +MT2
140J-3Hz-60% EIT +MT2
140J-3Hz-80% EIT +MT2
140J-10Hz-40% EIT +MT2
140J-10Hz-60% EIT +MT2
140J-10Hz-80% EIT +MT2
280J-3Hz-40% EIT +MT2
280J-3Hz-60% EIT +MT2
280J-3Hz-80% EIT +MT2
280J-10Hz-40% EIT +MT2
280J-10Hz-60% EIT +MT2
280J-10Hz-80% EIT +MT2
PSD after EI-Treatment and Milling Tests
Scheelite ore
Figure 20. PSD of material treated with (Samples EIT+MT) and without high-voltage electrical impulse
treatment (Raw Material) after the milling tests at 20 m/s
Q3 ,
%