238 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
(without high-voltage electrical impulse treatment) and
those with high-voltage electrical impulse treatment can be
found.
Mineral Liberation Analysis
One of the main objectives of comminution is to recover
the particles of the mineral of interest at the coarsest pos-
sible size. Ideally, this should be possible with a minimum
energy input. This is one of the potential advantages from
the high-voltage electrical impulse treatment.
The evaluation of the liberation occurs at three differ-
ent energy levels as well as two tests with similar energy
levels both using different combinations of impulse energy
and frequency.
The samples were taken from the fine material after
the treatment with the electrical impulses in the fraction
1 mm.
Table 5 summarizes the samples in which the MLA
Analysis is performed:
The approach of this work is to weaken the structure
of the material. A preferential liberation is expected, ideally
without overgrinding, i.e., in the coarse fractions. Mineral
phases liberated at this stage can be separated and do not
need to undergo further processing.
The mineral content for each sample was evaluated.
The actual mineral composition of the samples including
that of the raw material is shown in Figure 10.
Enrichment of ores means increasing the metal (or
nonmetal) content of an ore by removing as much of the
minerals in the ore that do not contain the desired sub-
stance. The enrichment ratio of the percentage of valuable
material in the concentrate to the percentage of the valuable
material in the original material. The degree of liberation
refers to the percentage of the mineral occurring as free par-
ticles in the ore in relation to the total content. The enrich-
ment factor and liberation degree were evaluated for mica.
The results are presented in Figure 11. As can be seen from
this figure, the mica shows an enrichment ratio between
1.34 and 1.73. Interestingly, the largest enrichment ratio
was measured on the sample with an energy input of only
1.18 kWh/t during the treatment with high-voltage electri-
cal impulses.
For determining the liberation degree, mica was sepa-
rated into the two varieties found in the samples: biotite
and muscovite. The results of the liberation degree as well
as the modal liberation can be found in Figure 13 and
Figure 13. From these figures, a different behavior between
the two micas is observed.
While biotite is liberated completely to ranges above
50% in all the samples, muscovite is poorly liberated,
exhibiting values from only about 2 to 5% and is found
mostly in combination with other minerals. This may be
explained based on the origin of these micas. While biotite
crystallises on its own, muscovite is produced by the altera-
tion of plagioclase (Popov, 2022). This can be visualized on
the example presented in Figure 14 and the results can be
seen in Figure 15.
Table 3. Selected experimental factors and levels for the
design of experiments used for testing granodiorite
Experimental Factor Unit Min Max Levels
A: Impulse Energy Joule 70 280 3
B: Impulse Frequency Hz 5.0 25.0 3
C: Flow Rate l/s 0.7 1.2 3
D: Feed of Material %40.0 80.0 3
70 J Impulse Energy 280
Experimental Factors:
Impulse Energy: 70 J, 175 J, 280 J
Frequency:5 Hz, 15 Hz, 25 Hz
Feed Rate: 40%, 60%, 80%
Pump flow rate:0,7 l/s, 0,95 l/s, 1,2 l/s
4
2 1
5
6
3
8
7
1 11
12
13,20,27
14
15
19
26
23
25
18
1
21
22
24
9
16
Figure 9. Schematic diagram showing the experimental Box-Behnken plan for the selected experimental factors (Box-Behnken
Plan representation adapted from (Lorenz)
40%
Feed
rate
80%
(without high-voltage electrical impulse treatment) and
those with high-voltage electrical impulse treatment can be
found.
Mineral Liberation Analysis
One of the main objectives of comminution is to recover
the particles of the mineral of interest at the coarsest pos-
sible size. Ideally, this should be possible with a minimum
energy input. This is one of the potential advantages from
the high-voltage electrical impulse treatment.
The evaluation of the liberation occurs at three differ-
ent energy levels as well as two tests with similar energy
levels both using different combinations of impulse energy
and frequency.
The samples were taken from the fine material after
the treatment with the electrical impulses in the fraction
1 mm.
Table 5 summarizes the samples in which the MLA
Analysis is performed:
The approach of this work is to weaken the structure
of the material. A preferential liberation is expected, ideally
without overgrinding, i.e., in the coarse fractions. Mineral
phases liberated at this stage can be separated and do not
need to undergo further processing.
The mineral content for each sample was evaluated.
The actual mineral composition of the samples including
that of the raw material is shown in Figure 10.
Enrichment of ores means increasing the metal (or
nonmetal) content of an ore by removing as much of the
minerals in the ore that do not contain the desired sub-
stance. The enrichment ratio of the percentage of valuable
material in the concentrate to the percentage of the valuable
material in the original material. The degree of liberation
refers to the percentage of the mineral occurring as free par-
ticles in the ore in relation to the total content. The enrich-
ment factor and liberation degree were evaluated for mica.
The results are presented in Figure 11. As can be seen from
this figure, the mica shows an enrichment ratio between
1.34 and 1.73. Interestingly, the largest enrichment ratio
was measured on the sample with an energy input of only
1.18 kWh/t during the treatment with high-voltage electri-
cal impulses.
For determining the liberation degree, mica was sepa-
rated into the two varieties found in the samples: biotite
and muscovite. The results of the liberation degree as well
as the modal liberation can be found in Figure 13 and
Figure 13. From these figures, a different behavior between
the two micas is observed.
While biotite is liberated completely to ranges above
50% in all the samples, muscovite is poorly liberated,
exhibiting values from only about 2 to 5% and is found
mostly in combination with other minerals. This may be
explained based on the origin of these micas. While biotite
crystallises on its own, muscovite is produced by the altera-
tion of plagioclase (Popov, 2022). This can be visualized on
the example presented in Figure 14 and the results can be
seen in Figure 15.
Table 3. Selected experimental factors and levels for the
design of experiments used for testing granodiorite
Experimental Factor Unit Min Max Levels
A: Impulse Energy Joule 70 280 3
B: Impulse Frequency Hz 5.0 25.0 3
C: Flow Rate l/s 0.7 1.2 3
D: Feed of Material %40.0 80.0 3
70 J Impulse Energy 280
Experimental Factors:
Impulse Energy: 70 J, 175 J, 280 J
Frequency:5 Hz, 15 Hz, 25 Hz
Feed Rate: 40%, 60%, 80%
Pump flow rate:0,7 l/s, 0,95 l/s, 1,2 l/s
4
2 1
5
6
3
8
7
1 11
12
13,20,27
14
15
19
26
23
25
18
1
21
22
24
9
16
Figure 9. Schematic diagram showing the experimental Box-Behnken plan for the selected experimental factors (Box-Behnken
Plan representation adapted from (Lorenz)
40%
Feed
rate
80%