186 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
than the particle feed size, avoiding that the particles are
exposed to simultaneous double-sided impacts when pass-
ing the gap.
The throughput for each test was at least 1 t resulting
in a test duration sufficiently long to reach the steady state
of the crusher operation and take a bulk sample during this
steady operation. Due to the timing of the overall proj-
ect, the number of tests had to be limited. So, the param-
eters to be investigated for their influence on Selective
Comminution was just the gap width. The rotor circumfer-
ence speed and the throughput for all tests were kept con-
stant at 40 m/s and 100 t/h, respectively. The repeatability
of the tests was investigated by repeating certain tests with
different durations and respective absolute throughputs. In
this case, the repeatability was found to be satisfying, with
the PSD showing hardly any deviation even with some sig-
nificantly longer test periods.
The Test Rig
The tests were conducted at the test facilities of the IART in
a commercially operated quarry nearby Freiberg (Figure 5).
The facility is equipped with various small industrial size
crushers, feeding/discharge systems, screening/laundering
units and dry storage facilities to conduct tests also with
larger samples.
The horizontal shaft impact crusher (HIS) was pro-
vided by BHS, Sonthofen. Figure 6 shows a side view with
the main dimensions of the machine. Feed is controlled by
a belt feeder. It was kept constant throughout the investiga-
tion. The crusher has a rotor with an impact diameter of
600 mm. The width of the impact bars is 240 mm.
Methodology of Analyzing the Results
After the tests, bulk samples of some 100 kg each were
taken and classified on a linear oscillating vibrating screen
(Haver Niagara, UME 450×1250 TG SPEZ). 12 screen
decks with apertures w =45, 31.5, 22.4, 16, 11.2, 8, 5.6,
4, 2.5, 2, 1.5, 1 mm, acc. to (German Industry Standard
DIN 323-2:1974-11) were used subsequently. The mass of
Table 3. Test program
Test No. Feed size [mm] Gap width [mm]
HAM18, PB-006 10/30 15
HAM18, PB-016 60
Figure 5. Test facilities (left) and impact crusher, open (right) (images: Lange)
Figure 6. Impact crusher -cross section and main
dimensions (Lange 2023)
than the particle feed size, avoiding that the particles are
exposed to simultaneous double-sided impacts when pass-
ing the gap.
The throughput for each test was at least 1 t resulting
in a test duration sufficiently long to reach the steady state
of the crusher operation and take a bulk sample during this
steady operation. Due to the timing of the overall proj-
ect, the number of tests had to be limited. So, the param-
eters to be investigated for their influence on Selective
Comminution was just the gap width. The rotor circumfer-
ence speed and the throughput for all tests were kept con-
stant at 40 m/s and 100 t/h, respectively. The repeatability
of the tests was investigated by repeating certain tests with
different durations and respective absolute throughputs. In
this case, the repeatability was found to be satisfying, with
the PSD showing hardly any deviation even with some sig-
nificantly longer test periods.
The Test Rig
The tests were conducted at the test facilities of the IART in
a commercially operated quarry nearby Freiberg (Figure 5).
The facility is equipped with various small industrial size
crushers, feeding/discharge systems, screening/laundering
units and dry storage facilities to conduct tests also with
larger samples.
The horizontal shaft impact crusher (HIS) was pro-
vided by BHS, Sonthofen. Figure 6 shows a side view with
the main dimensions of the machine. Feed is controlled by
a belt feeder. It was kept constant throughout the investiga-
tion. The crusher has a rotor with an impact diameter of
600 mm. The width of the impact bars is 240 mm.
Methodology of Analyzing the Results
After the tests, bulk samples of some 100 kg each were
taken and classified on a linear oscillating vibrating screen
(Haver Niagara, UME 450×1250 TG SPEZ). 12 screen
decks with apertures w =45, 31.5, 22.4, 16, 11.2, 8, 5.6,
4, 2.5, 2, 1.5, 1 mm, acc. to (German Industry Standard
DIN 323-2:1974-11) were used subsequently. The mass of
Table 3. Test program
Test No. Feed size [mm] Gap width [mm]
HAM18, PB-006 10/30 15
HAM18, PB-016 60
Figure 5. Test facilities (left) and impact crusher, open (right) (images: Lange)
Figure 6. Impact crusher -cross section and main
dimensions (Lange 2023)