XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 417
reject stockpile. (Figure 12) Average grade for this reject
material as reported by the MRA was 0.16% copper.
During a campaign of ~1 hour and 45 minutes, the
BOS functionality was disabled and 5,000 tonnes of the
rejected material was fed back to the gyratory crusher of the
primary sulphide processing circuit, making up the entirety
of the feed material. The coarse ore stockpile was drawn
down in advance of the campaign such that the reject
material would report without any delay and with minimal
cross-contamination to the grinding stage of the primary
sulphide circuit.
Samples were collected every five minutes for the dura-
tion of the campaign from the cyclone overflow sampling
point of the grinding circuit (refer to Figure 4). Samples
were assayed (AAS) for total copper content. The chart
below shows measurements collected by MRA and corre-
sponding sample assay grades for the campaign period, as
well as the periods immediately preceding and following
the campaign.
Figure 13 shows 24 hours of grade data from MRA
along with sample assay data for 19 May during the valida-
tion campaign. Sample assays from the cyclone overflow
decline for the duration of the campaign and reaching a
minimum grade of 0.17%Cu before climbing again after
completion of the campaign.
The results of the campaign demonstrate the effective-
ness of the BOS operations and are indicative of proper
functionality across both the analyser and diverting equip-
ment. Resulting data is consistent between the various
Figure 12. Approximately 10,000 tonnes of BOS reject material accumulated at KMP and used
for validation testing program
measurement methods: MRA %copper measurements
align with the cyclone O/F sample assays collected during
the trial. The sample assays exhibit a slightly positive bias
above the MRA, decreasing over time, as is expected con-
sidering recirculating loads of fresh ore fed prior to begin-
ning of the campaign. Further, the six-hour composite
assay from the Vezin sampler is consistent with both MRA
and O/F samples.
BULK SORTING RESULTS
Significant heterogeneity was observed in MRA grade mea-
surement data at the Kansanshi mine, supporting expecta-
tions based on the complex geological setting of the ore.
Operational mixing inherent in the Kansanshi operation
is minimal and represents an ideal setting for BOS. Ore is
loaded to trucks by shovels in the bench and tipped directly
to the crusher feed pocket, generally with no rehandle
although stockpiling does occur on occasion. As a result,
heterogeneity is preserved and strong bulk ore sorting
results can be achieved with installation of the BOS system
after the primary crusher.
Figure 14 shows typical grade fluctuations over a
24-hour period. An example, theoretical sorting cut-off
grade example is overlaid along with calculation of mass and
metal recovery. MRA grade measurements were observed to
frequently fluctuate at Kansanshi below 0.10% and above
2.50% copper within a matter of hours.
Mass recovery and metal recovery of BOS can be
adjusted by changing the BOS diverter cut-off grade. To
reject stockpile. (Figure 12) Average grade for this reject
material as reported by the MRA was 0.16% copper.
During a campaign of ~1 hour and 45 minutes, the
BOS functionality was disabled and 5,000 tonnes of the
rejected material was fed back to the gyratory crusher of the
primary sulphide processing circuit, making up the entirety
of the feed material. The coarse ore stockpile was drawn
down in advance of the campaign such that the reject
material would report without any delay and with minimal
cross-contamination to the grinding stage of the primary
sulphide circuit.
Samples were collected every five minutes for the dura-
tion of the campaign from the cyclone overflow sampling
point of the grinding circuit (refer to Figure 4). Samples
were assayed (AAS) for total copper content. The chart
below shows measurements collected by MRA and corre-
sponding sample assay grades for the campaign period, as
well as the periods immediately preceding and following
the campaign.
Figure 13 shows 24 hours of grade data from MRA
along with sample assay data for 19 May during the valida-
tion campaign. Sample assays from the cyclone overflow
decline for the duration of the campaign and reaching a
minimum grade of 0.17%Cu before climbing again after
completion of the campaign.
The results of the campaign demonstrate the effective-
ness of the BOS operations and are indicative of proper
functionality across both the analyser and diverting equip-
ment. Resulting data is consistent between the various
Figure 12. Approximately 10,000 tonnes of BOS reject material accumulated at KMP and used
for validation testing program
measurement methods: MRA %copper measurements
align with the cyclone O/F sample assays collected during
the trial. The sample assays exhibit a slightly positive bias
above the MRA, decreasing over time, as is expected con-
sidering recirculating loads of fresh ore fed prior to begin-
ning of the campaign. Further, the six-hour composite
assay from the Vezin sampler is consistent with both MRA
and O/F samples.
BULK SORTING RESULTS
Significant heterogeneity was observed in MRA grade mea-
surement data at the Kansanshi mine, supporting expecta-
tions based on the complex geological setting of the ore.
Operational mixing inherent in the Kansanshi operation
is minimal and represents an ideal setting for BOS. Ore is
loaded to trucks by shovels in the bench and tipped directly
to the crusher feed pocket, generally with no rehandle
although stockpiling does occur on occasion. As a result,
heterogeneity is preserved and strong bulk ore sorting
results can be achieved with installation of the BOS system
after the primary crusher.
Figure 14 shows typical grade fluctuations over a
24-hour period. An example, theoretical sorting cut-off
grade example is overlaid along with calculation of mass and
metal recovery. MRA grade measurements were observed to
frequently fluctuate at Kansanshi below 0.10% and above
2.50% copper within a matter of hours.
Mass recovery and metal recovery of BOS can be
adjusted by changing the BOS diverter cut-off grade. To