XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 515
can be noticed that the difficulty in screening with increase
in moisture (Figure 5). The efficiency at 12.7% for 3.2
and 2.5 mm Urethane panel measured at actual cut point
are around 80% mark which is a lot better than expected.
The test 7 shows the best results at 12.7% feed moisture
with +2 mm in undersize of 5.6% and achieving undersize
weight recovery of near 70%.
It can be easily concluded that the Derrick dry screens
can be used to screen iron ore with moisture of upto 10%
while achieving sub 90% efficiency. The results on the
above application motivates the new work in dry mineral
processing space where there is some moisture while screen-
ing (Figure 6).
The similar application of screening iron ore at 1.5 to
2 mm is common for close circuiting HPGR circuits for
better energy efficiency of the energy intensive comminu-
tion circuit.
CONCLUSIONS
The shift towards dry mineral processing presents a signifi-
cant advancement in the mining industry, offering a more
sustainable and environmentally conscious approach. The
focus on precise particle size separation plays a crucial role
in optimizing product grade and mineral recovery. Various
technologies, such as cyclones, hindered settling classifi-
ers, and screens, are employed in dry mineral processing
operations.
Dry fine screens, categorized by shape and motion, are
vital in achieving desired product specifications. Advances
in screening technology, including self-cleaning panels,
exemplify the industry’s commitment to enhanced dura-
bility and efficiency. Factors affecting dry screening, such
as moisture, angle of repose, bulk density, particle size dis-
tribution, particle shape, vibration frequency, amplitude,
temperature, and chemical compatibility, need careful
consideration.
Table 2. Test results of iron ore dry screening
Actual Machine %Ave. %Ave.
Test Cut Angle Moisture Weight Weight Oversize Undersize Overall
No. Microns (degrees) (MTPH) (%)Recovery Recovery (%)(%)(%)
1 Urethane 2500 1700 35 33.7 3.5 28.8 73.5 71.2 1.1 90.7 91.4 91.2
2 Urethane 2500 2000 30 30.2 3.5 23.5 74.4 76.5 2.1 90.4 93.4 92.9
3 Urethane 3200 2360 30 31.0 3.5 15.6 78.5 84.4 5.9 85.5 96.2 94.7
4 Wire Sandwich 3530 2800 30 34.9 3.5 14.3 81.1 85.7 7.0 95.2 97.3 97.1
5 Wire Sandwich 3530 2800 30 37.9 7.1 39.2 37.2 60.8 7.5 95.5 81.4 82.9
6 Urethane 3200 2800 30 36.6 7.1 41.8 30.8 58.2 6.4 94.6 75.5 77.5
7 Urethane 3200 2360 30 40.5 12.7 30.1 40.4 69.9 5.6 90.4 77.7 79.5
8 Urethane 2500 2000 30 38.9 12.7 34.2 53.1 65.8 1.4 95.3 79.9 82.9
Screen Dry Screen Test Results with Iron Ore
Feed 1 Oversize Undersize
%Coarse
at
separation
%Plus
2 mm
Efficiency at actual cut point
Panel
Opening
(microns)
Material type
0
10
20
30
40
50
60
70
80
90
100
0 2 4 6 8 10 12 14
%Moisture
Screening Efficiency at different moisture with 3.2 mm urethane panel
Figure 5. Decreasing Screening efficiency with increasing feed moisture
%
Overall
Efficiency
can be noticed that the difficulty in screening with increase
in moisture (Figure 5). The efficiency at 12.7% for 3.2
and 2.5 mm Urethane panel measured at actual cut point
are around 80% mark which is a lot better than expected.
The test 7 shows the best results at 12.7% feed moisture
with +2 mm in undersize of 5.6% and achieving undersize
weight recovery of near 70%.
It can be easily concluded that the Derrick dry screens
can be used to screen iron ore with moisture of upto 10%
while achieving sub 90% efficiency. The results on the
above application motivates the new work in dry mineral
processing space where there is some moisture while screen-
ing (Figure 6).
The similar application of screening iron ore at 1.5 to
2 mm is common for close circuiting HPGR circuits for
better energy efficiency of the energy intensive comminu-
tion circuit.
CONCLUSIONS
The shift towards dry mineral processing presents a signifi-
cant advancement in the mining industry, offering a more
sustainable and environmentally conscious approach. The
focus on precise particle size separation plays a crucial role
in optimizing product grade and mineral recovery. Various
technologies, such as cyclones, hindered settling classifi-
ers, and screens, are employed in dry mineral processing
operations.
Dry fine screens, categorized by shape and motion, are
vital in achieving desired product specifications. Advances
in screening technology, including self-cleaning panels,
exemplify the industry’s commitment to enhanced dura-
bility and efficiency. Factors affecting dry screening, such
as moisture, angle of repose, bulk density, particle size dis-
tribution, particle shape, vibration frequency, amplitude,
temperature, and chemical compatibility, need careful
consideration.
Table 2. Test results of iron ore dry screening
Actual Machine %Ave. %Ave.
Test Cut Angle Moisture Weight Weight Oversize Undersize Overall
No. Microns (degrees) (MTPH) (%)Recovery Recovery (%)(%)(%)
1 Urethane 2500 1700 35 33.7 3.5 28.8 73.5 71.2 1.1 90.7 91.4 91.2
2 Urethane 2500 2000 30 30.2 3.5 23.5 74.4 76.5 2.1 90.4 93.4 92.9
3 Urethane 3200 2360 30 31.0 3.5 15.6 78.5 84.4 5.9 85.5 96.2 94.7
4 Wire Sandwich 3530 2800 30 34.9 3.5 14.3 81.1 85.7 7.0 95.2 97.3 97.1
5 Wire Sandwich 3530 2800 30 37.9 7.1 39.2 37.2 60.8 7.5 95.5 81.4 82.9
6 Urethane 3200 2800 30 36.6 7.1 41.8 30.8 58.2 6.4 94.6 75.5 77.5
7 Urethane 3200 2360 30 40.5 12.7 30.1 40.4 69.9 5.6 90.4 77.7 79.5
8 Urethane 2500 2000 30 38.9 12.7 34.2 53.1 65.8 1.4 95.3 79.9 82.9
Screen Dry Screen Test Results with Iron Ore
Feed 1 Oversize Undersize
%Coarse
at
separation
%Plus
2 mm
Efficiency at actual cut point
Panel
Opening
(microns)
Material type
0
10
20
30
40
50
60
70
80
90
100
0 2 4 6 8 10 12 14
%Moisture
Screening Efficiency at different moisture with 3.2 mm urethane panel
Figure 5. Decreasing Screening efficiency with increasing feed moisture
%
Overall
Efficiency