190 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
sphalerite to break of and report to the fine fractions, really
a textbook case of Selective Comminution.
For the cassiterite, despite also being bridle, such a
remarkable enrichment could not be shown in the same
process. Obviously, the cassiterite was not concentrated in
the visible veins but rather intergrown with other materials
in the rocks. Since the gentle stress hardly caused the larger
lumps to break, the cassiterite could not be liberated in the
same process. While this may appear a bit disappointing at
first glance, one may also consider this an opportunity to
separate the various valuable metal minerals by this simple
mechanical process rather than applying more expensive
sorting technologies such as flotation or so.
CONCLUSION
The results of our research show that there is an interesting
opportunity in exploiting the selectivity in the comminu-
tion of a complex skarn ore containing significant amounts
of zinc. Even with a gentle comminution of the ore in an
impact crusher, hardly reducing the median particle size,
already a significant amount of the zinc is deported to
the fine fractions. In the case of more intense stressing of
the material using a smaller crushing gap, almost 60% of
the overall zinc is deported to the fraction 1mm, which
allows the generation of a good pre-concentrate by a simple
screening step. This shows the interesting opportunities in
the Selective Comminution using a horizontal shaft impact
crusher.
ACKNOWLEDGMENT
We would like to thank the AFK-project, funded within
the German r4-initiative of the BMBF (grant number
033R128) for providing the test material.
LITERATURVERZEICHNIS
Ballantyne, G.R., Powell, M.S. (2014), Benchmarking
comminution energy consumption for the processing
of copper and gold ores. In: Minerals Engineering 65, S.
109–114. doi: 10.1016/j.mineng.2014.05.017.
European Commission (2016). Raw materials scoreboard.
European Partnership on Raw Materials.
Hertwich, E., Lifset, R., Pauliuk, S., Heeren, N. (2020),
Resource efficiency and climate change. Material effi-
ciency strategies for a low-carbon future. A report of
the International Resource Panel. United Nations
Environment Programme. Nairobi, Kenia. www.
resourcepanel.org/reports/resource-efficiency-and
-climate-change
Hesse, M. (2017), Selektive Zerkleinerung von Erzen
und Industriemineralen bei Prallbeanspruchung.
Dissertation. TU Bergakademie Freiberg, Freiberg.
Höffl, K. (2006), Zerkleinerungs- und Klassiermaschinen.
2. Aufl. Hannover: Schlüthersche Verlagsanstalt und
Druckerei GmbH &Co.
0
10
20
30
40
50
60
Fraction [mm]
Relative Mass Content of Zinc and Gangue Material
HAM18, PB-006
Zinc Gangue
Figure 10. Relative mass content of valuable gangue materia in the various fractions at 15 mm crushing
gap (test HAM18, PB-006)
Relative
mass
c
tent
[%]
sphalerite to break of and report to the fine fractions, really
a textbook case of Selective Comminution.
For the cassiterite, despite also being bridle, such a
remarkable enrichment could not be shown in the same
process. Obviously, the cassiterite was not concentrated in
the visible veins but rather intergrown with other materials
in the rocks. Since the gentle stress hardly caused the larger
lumps to break, the cassiterite could not be liberated in the
same process. While this may appear a bit disappointing at
first glance, one may also consider this an opportunity to
separate the various valuable metal minerals by this simple
mechanical process rather than applying more expensive
sorting technologies such as flotation or so.
CONCLUSION
The results of our research show that there is an interesting
opportunity in exploiting the selectivity in the comminu-
tion of a complex skarn ore containing significant amounts
of zinc. Even with a gentle comminution of the ore in an
impact crusher, hardly reducing the median particle size,
already a significant amount of the zinc is deported to
the fine fractions. In the case of more intense stressing of
the material using a smaller crushing gap, almost 60% of
the overall zinc is deported to the fraction 1mm, which
allows the generation of a good pre-concentrate by a simple
screening step. This shows the interesting opportunities in
the Selective Comminution using a horizontal shaft impact
crusher.
ACKNOWLEDGMENT
We would like to thank the AFK-project, funded within
the German r4-initiative of the BMBF (grant number
033R128) for providing the test material.
LITERATURVERZEICHNIS
Ballantyne, G.R., Powell, M.S. (2014), Benchmarking
comminution energy consumption for the processing
of copper and gold ores. In: Minerals Engineering 65, S.
109–114. doi: 10.1016/j.mineng.2014.05.017.
European Commission (2016). Raw materials scoreboard.
European Partnership on Raw Materials.
Hertwich, E., Lifset, R., Pauliuk, S., Heeren, N. (2020),
Resource efficiency and climate change. Material effi-
ciency strategies for a low-carbon future. A report of
the International Resource Panel. United Nations
Environment Programme. Nairobi, Kenia. www.
resourcepanel.org/reports/resource-efficiency-and
-climate-change
Hesse, M. (2017), Selektive Zerkleinerung von Erzen
und Industriemineralen bei Prallbeanspruchung.
Dissertation. TU Bergakademie Freiberg, Freiberg.
Höffl, K. (2006), Zerkleinerungs- und Klassiermaschinen.
2. Aufl. Hannover: Schlüthersche Verlagsanstalt und
Druckerei GmbH &Co.
0
10
20
30
40
50
60
Fraction [mm]
Relative Mass Content of Zinc and Gangue Material
HAM18, PB-006
Zinc Gangue
Figure 10. Relative mass content of valuable gangue materia in the various fractions at 15 mm crushing
gap (test HAM18, PB-006)
Relative
mass
c
tent
[%]