XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3867
for each test can be determined under consideration of the
power for idling and the feed material throughput.
.79 .W m
P P
1000
159
0.09h
8 39
h
t
kW
t
kWh
omo
feed
0 =
-
=
-
=
^1.43
`j
(2)
This calculation method is independent of the different
milling operation modes, because the fresh feed material is
always fed in dry condition.
Analyzing the Samples
Each sample PSD is transferred into a distribution according
to Rosin-Rammler-Sperling-Bennet (RRSB-distribution).
A Sample for such a transformation is given in the diagram
at Figure 9.
In the diagram four samples from the test No. 1 (see
Figure 7 and Figure 8) are shown. The sampling point can
be comprehended according to Figure 2. On the very top
of the figure, each calculated shape and scale parameter is
given to the corresponding sample number. Apparently,
the screening fines, the milling product and the fresh feed
material fits quite well to the RRSB-distribution. Only the
screening coarse has a larger deviation. This is surely attrib-
uted to the fact that the screening coarse mainly missing the
fines and therefore its spitted into two main sections. The
section above the screen cut size is following the milling
product, while the section smaller than the cut size misses
the mentioned fines.
In order to have generalized PSD´s for the different
parameter settings, the means of the different shape and
scale parameters are calculated.
RESULTS AND DISCUSSION
The results, as listed in Table 2, are calculated according to
the described procedure and parameter settings mentioned
in Table 1. The test No. 1 is the one used as example. In
summary, over 4,000 kg of the test material were used for
the first milling tests, which are presented and discussed
below.
Nineteen dry milling tests and one wet milling test are
listed on the table. Furthermore, most parameter combina-
tions have been tested at least three times. Therefore, the
scatter of the results of the dry milling tests can be estimated.
The wet milling test was carried out at approximately
15 %moisture content. The fresh material was fed in dry
condition and was moisturized over a hose in the mill feed
chute. During the test, the flow of water was recorded. In
this case a volume of approximately 0.024 m3/h was added
to simulate a moist feed material. About 3.7 m3/h of water
was added within the screening machine, to provide a good
Figure 8. Time series of mechanical energy demand and feed material throughput for test No. 1
for each test can be determined under consideration of the
power for idling and the feed material throughput.
.79 .W m
P P
1000
159
0.09h
8 39
h
t
kW
t
kWh
omo
feed
0 =
-
=
-
=
^1.43
`j
(2)
This calculation method is independent of the different
milling operation modes, because the fresh feed material is
always fed in dry condition.
Analyzing the Samples
Each sample PSD is transferred into a distribution according
to Rosin-Rammler-Sperling-Bennet (RRSB-distribution).
A Sample for such a transformation is given in the diagram
at Figure 9.
In the diagram four samples from the test No. 1 (see
Figure 7 and Figure 8) are shown. The sampling point can
be comprehended according to Figure 2. On the very top
of the figure, each calculated shape and scale parameter is
given to the corresponding sample number. Apparently,
the screening fines, the milling product and the fresh feed
material fits quite well to the RRSB-distribution. Only the
screening coarse has a larger deviation. This is surely attrib-
uted to the fact that the screening coarse mainly missing the
fines and therefore its spitted into two main sections. The
section above the screen cut size is following the milling
product, while the section smaller than the cut size misses
the mentioned fines.
In order to have generalized PSD´s for the different
parameter settings, the means of the different shape and
scale parameters are calculated.
RESULTS AND DISCUSSION
The results, as listed in Table 2, are calculated according to
the described procedure and parameter settings mentioned
in Table 1. The test No. 1 is the one used as example. In
summary, over 4,000 kg of the test material were used for
the first milling tests, which are presented and discussed
below.
Nineteen dry milling tests and one wet milling test are
listed on the table. Furthermore, most parameter combina-
tions have been tested at least three times. Therefore, the
scatter of the results of the dry milling tests can be estimated.
The wet milling test was carried out at approximately
15 %moisture content. The fresh material was fed in dry
condition and was moisturized over a hose in the mill feed
chute. During the test, the flow of water was recorded. In
this case a volume of approximately 0.024 m3/h was added
to simulate a moist feed material. About 3.7 m3/h of water
was added within the screening machine, to provide a good
Figure 8. Time series of mechanical energy demand and feed material throughput for test No. 1