XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 503
cause of the observed phenomenon is thus far, and whether
these characteristics are universal or specific to this particu-
lar sample.
As the plot above demonstrates, there is a strong cor-
relation between Feed Fe concentration and Delta Fe in the
product. Scavenger 1 is the obvious outlier. Further testing
with progressively lower Feed Fe concentrations would be
necessary to determine the extent of this trend, and subse-
quent mineralogical analysis of the feed samples could elu-
cidate the root cause of this phenomenon.
Following the completion of the first and second pass
separation testing three different processing schemes were
created to target different outcomes. Scheme 1 targeted a
high grade final product at the expense of yield. Scheme
2 balanced the yield and grade of the final product, creat-
ing a moderately enriched product at a higher yield than
Scheme 1. Scheme 3 sacrificed product grade to maximize
yield. The results of the three processing schemes developed
from the testing are described in Table 7.
All three schemes use multiple separators to achieve
their respective results. Scheme 1 used both scavenging and
cleaning separators, with the scavenger serving to boost the
yield. Schemes 2 and 3 used only a scavenger, the cleaner
separator was omitted to eliminate the sharp reduction
in yield. Feed rates for ultrafine processing have not been
optimized. Diagrams of the three schemes are shown in
Figures 8–10.
Air-Classified Iron Ore Separation Results
Similar variable optimization and investigation of process-
ing schemes were conducted for the “air-classified” iron ore
sample.
Scheme 1 targeted a high Fe recovery and a high-grade
final product using rougher, followed by a cleaner. Scheme
2 targeted a mid-grade product and increased recovery
using a scavenger. Scheme 3 targeted a high-grade product
at the rougher stage and then a scavenger stage can be used
to increase overall recovery.
The results of the three processing schemes developed
from the testing are described in Table 8. The feed rates
are estimated from the test results assuming a single STET
Model M42 separator for each stage.
R² =0.8022
R² =0.9976
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
30.0 35.0 40.0 45.0 50.0 55.0 60.0
Feed Fe
Scavenger 1
Scavenger 2
Scavenger 3
Cleaner 1
Cleaner 2
Cleaner 3
Poly. (Overall Trend)
Poly. (Overall Trend,
Excluding Scavenger 1)
Figure 7. Plot showing the relationship between feed Fe and Fe increase
Table 7. Summary of the results for different first- and second-pass combination schemes
Scheme Product Mass Yield Fe Recovery Product Fe Content
High grade product with cleaner
and scavenger
31.9% 40.8% 59.2%
Mid grade product and scavenger 54.9% 65.9% 55.4%
Low grade product with scavenger -
high Recovery Scheme
73.8% 82.3% 51.5%
Delta
Fe
cause of the observed phenomenon is thus far, and whether
these characteristics are universal or specific to this particu-
lar sample.
As the plot above demonstrates, there is a strong cor-
relation between Feed Fe concentration and Delta Fe in the
product. Scavenger 1 is the obvious outlier. Further testing
with progressively lower Feed Fe concentrations would be
necessary to determine the extent of this trend, and subse-
quent mineralogical analysis of the feed samples could elu-
cidate the root cause of this phenomenon.
Following the completion of the first and second pass
separation testing three different processing schemes were
created to target different outcomes. Scheme 1 targeted a
high grade final product at the expense of yield. Scheme
2 balanced the yield and grade of the final product, creat-
ing a moderately enriched product at a higher yield than
Scheme 1. Scheme 3 sacrificed product grade to maximize
yield. The results of the three processing schemes developed
from the testing are described in Table 7.
All three schemes use multiple separators to achieve
their respective results. Scheme 1 used both scavenging and
cleaning separators, with the scavenger serving to boost the
yield. Schemes 2 and 3 used only a scavenger, the cleaner
separator was omitted to eliminate the sharp reduction
in yield. Feed rates for ultrafine processing have not been
optimized. Diagrams of the three schemes are shown in
Figures 8–10.
Air-Classified Iron Ore Separation Results
Similar variable optimization and investigation of process-
ing schemes were conducted for the “air-classified” iron ore
sample.
Scheme 1 targeted a high Fe recovery and a high-grade
final product using rougher, followed by a cleaner. Scheme
2 targeted a mid-grade product and increased recovery
using a scavenger. Scheme 3 targeted a high-grade product
at the rougher stage and then a scavenger stage can be used
to increase overall recovery.
The results of the three processing schemes developed
from the testing are described in Table 8. The feed rates
are estimated from the test results assuming a single STET
Model M42 separator for each stage.
R² =0.8022
R² =0.9976
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
30.0 35.0 40.0 45.0 50.0 55.0 60.0
Feed Fe
Scavenger 1
Scavenger 2
Scavenger 3
Cleaner 1
Cleaner 2
Cleaner 3
Poly. (Overall Trend)
Poly. (Overall Trend,
Excluding Scavenger 1)
Figure 7. Plot showing the relationship between feed Fe and Fe increase
Table 7. Summary of the results for different first- and second-pass combination schemes
Scheme Product Mass Yield Fe Recovery Product Fe Content
High grade product with cleaner
and scavenger
31.9% 40.8% 59.2%
Mid grade product and scavenger 54.9% 65.9% 55.4%
Low grade product with scavenger -
high Recovery Scheme
73.8% 82.3% 51.5%
Delta
Fe