4
For example, a slightly stronger magnet in the cleaner stage
can reduce the mass of the “Nonmags” here.
After reviewing the cleaner circuit where the gauss level
was decreased from 3000 gauss to 1000 gauss, the effect
was to increase the yield and the iron grade. The iron lost
to waste can be reduced by increasing the intensity of the
gauss on the drum or increasing the drum rotation speed.
What is of essential consideration is looking at the
material that is being passed to the milling circuit. If a
magnetic circuit is not installed and elects to grind all the
material through the milling circuit, a larger mill needs to
handle 1000tph feed. However, using a magnetic circuit
reduces the feed by 40.6% by removing gangue material
before milling, dramatically reducing the installed size and
power. The client now has a choice to either maintain the
size of the mill selected and increase the processing feed
rate or achieve the planned production rate but consume
less power.
Dewatering Circuit
Recent work has shown the effectiveness of STEINERT’s
installation of dewatering drums, which has helped a cen-
tral Queensland mining operation overcome a bottleneck
in a magnetite concentrate drying circuit.
The concentrate is pumped to the dewatering drums.
Typical pulp slurry densities of 63 to 65% result in a nomi-
nal feed rate of 150 to 170tph to a ceramic disc filter. The
site had one 45m diameter thickener tank needed for the
concentrate dewatering circuit. An additional thickener
tank and a larger drying capacity were required for the cir-
cuit to increase capacity through the plant. The alternative
STEINERT Australia offered was to introduce dewatering
drums for the application, which eliminated the need for
the additional thickening tank, and the existing ceramic fil-
ters did not need to be increased.
Figure 6 shows how increasing the solids density from
63% to 75% of the capacity throughput yielded a nominal
tonnage increase of 110tph or a 65% effective increase in
throughput. The drying capacity increased from 1200kg/
m2 to 2000kg/m2, effectively a 66.7% increase!
As demonstrated in Table 1, the advantages of the alter-
native dewatering drums system were increased through-
put capacity with fewer filters. The energy savings bought
for the project was 210kW. A key area often overlooked is
the smaller real estate footprint, leading to significant sav-
ings in civil works and installation costs and lower capital
investment.
This shows the Cost and power analysis between tradi-
tional circuit vs Dewatering drum solution.
Table 1.
Thickener Dewatering Drums
Qty Required 2 36
Size 045m 01220 × 1,8m wide
Total area required ~4500m2 ~420m2
Installation cost ~A$36m** A$26.5m**
Power consumption 20 kW 198 kW
Discharge Solids
concentration
72% solids w/w 70–85% solids w/w
Number of filters
required
13' 10*
Filters’ power
consumption
910 kW* 700 kW*
Cost of filters ~$19.5m** ~$15m**
Figure 6.
For example, a slightly stronger magnet in the cleaner stage
can reduce the mass of the “Nonmags” here.
After reviewing the cleaner circuit where the gauss level
was decreased from 3000 gauss to 1000 gauss, the effect
was to increase the yield and the iron grade. The iron lost
to waste can be reduced by increasing the intensity of the
gauss on the drum or increasing the drum rotation speed.
What is of essential consideration is looking at the
material that is being passed to the milling circuit. If a
magnetic circuit is not installed and elects to grind all the
material through the milling circuit, a larger mill needs to
handle 1000tph feed. However, using a magnetic circuit
reduces the feed by 40.6% by removing gangue material
before milling, dramatically reducing the installed size and
power. The client now has a choice to either maintain the
size of the mill selected and increase the processing feed
rate or achieve the planned production rate but consume
less power.
Dewatering Circuit
Recent work has shown the effectiveness of STEINERT’s
installation of dewatering drums, which has helped a cen-
tral Queensland mining operation overcome a bottleneck
in a magnetite concentrate drying circuit.
The concentrate is pumped to the dewatering drums.
Typical pulp slurry densities of 63 to 65% result in a nomi-
nal feed rate of 150 to 170tph to a ceramic disc filter. The
site had one 45m diameter thickener tank needed for the
concentrate dewatering circuit. An additional thickener
tank and a larger drying capacity were required for the cir-
cuit to increase capacity through the plant. The alternative
STEINERT Australia offered was to introduce dewatering
drums for the application, which eliminated the need for
the additional thickening tank, and the existing ceramic fil-
ters did not need to be increased.
Figure 6 shows how increasing the solids density from
63% to 75% of the capacity throughput yielded a nominal
tonnage increase of 110tph or a 65% effective increase in
throughput. The drying capacity increased from 1200kg/
m2 to 2000kg/m2, effectively a 66.7% increase!
As demonstrated in Table 1, the advantages of the alter-
native dewatering drums system were increased through-
put capacity with fewer filters. The energy savings bought
for the project was 210kW. A key area often overlooked is
the smaller real estate footprint, leading to significant sav-
ings in civil works and installation costs and lower capital
investment.
This shows the Cost and power analysis between tradi-
tional circuit vs Dewatering drum solution.
Table 1.
Thickener Dewatering Drums
Qty Required 2 36
Size 045m 01220 × 1,8m wide
Total area required ~4500m2 ~420m2
Installation cost ~A$36m** A$26.5m**
Power consumption 20 kW 198 kW
Discharge Solids
concentration
72% solids w/w 70–85% solids w/w
Number of filters
required
13' 10*
Filters’ power
consumption
910 kW* 700 kW*
Cost of filters ~$19.5m** ~$15m**
Figure 6.