XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 207
selective shift of copper into the finer fraction shows some
promise for HPSA’s ability to pre-concentrate the copper
into the finer fraction, which can then be separated from
the coarser material that has lower grade. This would allow
for a size separation prior to flotation that would increase
the grade entering rougher flotation and potentially yield
higher grades and recoveries of copper bearing minerals.
CONTINUOUS TESTING CASE:
PHOSPHATE
In a phosphate application, HPSA uses the base phosphate
mineral (hydroxyapatite) to liberate acid consuming miner-
als and silicate from the phosphate rock. Figure 13 displays
that HPSA processing increased the content of apatite in
the +44 µm (+325 US mesh) by 3%, while also increas-
ing total apatite recovery by an average of 4%. Figure 13
further details the MLA results, showing apatite liberated
in the +149 µm (+100 US mesh) size fraction and gangue
minerals concentrated in the –44 µm (–325 US mesh) size
fraction. Furthermore,
Table 3 displays HPSA processing was able to increase
apatite grade by an average of 5% while, decreasing silica
and magnesia gangue by 4.8% and 0.4%, respectively.
The initial optimization results concluded that HPSA
effectively liberated acid consumers and insoluble minerals
into the fine fraction, leading to an increase in both grade
and recovery. HPSA’s selective liberation also decreased the
amount of material required for downstream processing,
resulting in savings for pipeline transportation and phos-
phoric acid plant processing. Reduction of phosphoric acid
plant processing has environmental benefits such as the
reduction of sulfuric acid use and mitigating the hazardous
byproduct phosphogypsum. In this case, a technoeconomic
analysis (TEA) was developed to quantify potential value
added. The TEA calculated that the implementation of a 5
tph HPSA unit has potential to add up to $500,000/year
in economic value. Furthermore, a 250 tph HPSA unit has
the potential to add $26 M/year in economic value.
A 5 tph continuous Gen Bravo HPSA unit was
installed in a phosphate milling circuit in December 2023,
shown in Figure 14. The engineering unit has a target
Figure 13.Phosphate MLA results pre-HPSA (left) and post-HPSA (right)
Table 3. Phosphate Optimization Testing. HPSA Product Comparison to Rod Mill Product
Test No. HPSA Operation Time
P2O5 Grade
Increase
P2O5 Recovery
Increase
SiO2 Conc.
Decrease
MgO Conc.
Decrease
1 5 min 2.9% 8.3% 2.3% 0.3%
10 min 3.8% 5.0% 4.2% 0.3%
15 min 4.7% 2.9% 4.9% 0.3%
2 5 min 4.2% 6.4% 3.3% 0.2%
10 min 5.0% 3.4% 4.1% 0.3%
selective shift of copper into the finer fraction shows some
promise for HPSA’s ability to pre-concentrate the copper
into the finer fraction, which can then be separated from
the coarser material that has lower grade. This would allow
for a size separation prior to flotation that would increase
the grade entering rougher flotation and potentially yield
higher grades and recoveries of copper bearing minerals.
CONTINUOUS TESTING CASE:
PHOSPHATE
In a phosphate application, HPSA uses the base phosphate
mineral (hydroxyapatite) to liberate acid consuming miner-
als and silicate from the phosphate rock. Figure 13 displays
that HPSA processing increased the content of apatite in
the +44 µm (+325 US mesh) by 3%, while also increas-
ing total apatite recovery by an average of 4%. Figure 13
further details the MLA results, showing apatite liberated
in the +149 µm (+100 US mesh) size fraction and gangue
minerals concentrated in the –44 µm (–325 US mesh) size
fraction. Furthermore,
Table 3 displays HPSA processing was able to increase
apatite grade by an average of 5% while, decreasing silica
and magnesia gangue by 4.8% and 0.4%, respectively.
The initial optimization results concluded that HPSA
effectively liberated acid consumers and insoluble minerals
into the fine fraction, leading to an increase in both grade
and recovery. HPSA’s selective liberation also decreased the
amount of material required for downstream processing,
resulting in savings for pipeline transportation and phos-
phoric acid plant processing. Reduction of phosphoric acid
plant processing has environmental benefits such as the
reduction of sulfuric acid use and mitigating the hazardous
byproduct phosphogypsum. In this case, a technoeconomic
analysis (TEA) was developed to quantify potential value
added. The TEA calculated that the implementation of a 5
tph HPSA unit has potential to add up to $500,000/year
in economic value. Furthermore, a 250 tph HPSA unit has
the potential to add $26 M/year in economic value.
A 5 tph continuous Gen Bravo HPSA unit was
installed in a phosphate milling circuit in December 2023,
shown in Figure 14. The engineering unit has a target
Figure 13.Phosphate MLA results pre-HPSA (left) and post-HPSA (right)
Table 3. Phosphate Optimization Testing. HPSA Product Comparison to Rod Mill Product
Test No. HPSA Operation Time
P2O5 Grade
Increase
P2O5 Recovery
Increase
SiO2 Conc.
Decrease
MgO Conc.
Decrease
1 5 min 2.9% 8.3% 2.3% 0.3%
10 min 3.8% 5.0% 4.2% 0.3%
15 min 4.7% 2.9% 4.9% 0.3%
2 5 min 4.2% 6.4% 3.3% 0.2%
10 min 5.0% 3.4% 4.1% 0.3%