XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1393
SCOPE OF WORK
The seven samples were all treated in the same way, aiming
to provide fragments suitable for standard and small frag-
ment HIT testing using selected size fraction in the target
–2 mm range. Figure 3 shows the key steps of the workflow
employed by BML. A description of these steps follows.
Sample Selection for Standard HIT Axb Tests
After reviewing the available material post initial crushing
of the lump samples it was clear that there would be suffi-
cient fragments to undertake standard HIT Axb tests using
triplicate splits of fragments in the 22.4×19 mm size frac-
tion. Figure 4 shows one split of 10 fragments for all seven
samples supplied for the trials.
Results from Standard HIT Axb Tests
The results from the standard HIT Axb tests completed by
BML are shown in Table 2. The format shows the results for
each split of 10 rocks across the 7 samples supplied by RT,
including the average fragment mass in the 22.4×19 mm
size fraction, specific comminution energy and Axb.
The table also shows the average Axb for each of the
seven samples and standard deviation indicating variabil-
ity within each sample. The standard HIT Axb tests sug-
gest sample 4, weathered siltstone, has the lowest impact
resistance with an Axb of 331. The sample with the highest
impact resistance is sample 3, siltstone, having an Axb of
32. The variability within each of the 7 samples, as defined
by the coefficient of variation (CoV) or SD/Mean, ranges
from 3% for sample 5, milky quartz, to 20% for sample
2, basalt. The average Axb CoV is around 11%, compared
to only 6% for the average fragment mass. The fragment
mass CoV ranges from 4% to 10% across the seven sam-
ples. There is no evidence to suggest variation in fragment
mass translates to variation in impact hardness as expressed
by Axb.
Figure 3. Flowsheet showing workflow applied to all 7 samples
SCOPE OF WORK
The seven samples were all treated in the same way, aiming
to provide fragments suitable for standard and small frag-
ment HIT testing using selected size fraction in the target
–2 mm range. Figure 3 shows the key steps of the workflow
employed by BML. A description of these steps follows.
Sample Selection for Standard HIT Axb Tests
After reviewing the available material post initial crushing
of the lump samples it was clear that there would be suffi-
cient fragments to undertake standard HIT Axb tests using
triplicate splits of fragments in the 22.4×19 mm size frac-
tion. Figure 4 shows one split of 10 fragments for all seven
samples supplied for the trials.
Results from Standard HIT Axb Tests
The results from the standard HIT Axb tests completed by
BML are shown in Table 2. The format shows the results for
each split of 10 rocks across the 7 samples supplied by RT,
including the average fragment mass in the 22.4×19 mm
size fraction, specific comminution energy and Axb.
The table also shows the average Axb for each of the
seven samples and standard deviation indicating variabil-
ity within each sample. The standard HIT Axb tests sug-
gest sample 4, weathered siltstone, has the lowest impact
resistance with an Axb of 331. The sample with the highest
impact resistance is sample 3, siltstone, having an Axb of
32. The variability within each of the 7 samples, as defined
by the coefficient of variation (CoV) or SD/Mean, ranges
from 3% for sample 5, milky quartz, to 20% for sample
2, basalt. The average Axb CoV is around 11%, compared
to only 6% for the average fragment mass. The fragment
mass CoV ranges from 4% to 10% across the seven sam-
ples. There is no evidence to suggest variation in fragment
mass translates to variation in impact hardness as expressed
by Axb.
Figure 3. Flowsheet showing workflow applied to all 7 samples