498 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
A design of experiment approach was used to evalu-
ate the factors (variables) that can be used to affect sepa-
ration on the STET tribo-electrostatic machine for both
“ultrafines” and “air-classified” iron ore samples. The design
was constructed using JMP software, whereby the model
included main effects, second order effects, and quadratic
interactions of continuous variables. Table 4 shows the fac-
tors and their respective levels that were tested.
Figure 2. (s) Particle size distribution by cumulative volume (“Ultrafines” –10 µm) (b) Particle size distribution by cumulative
volume (“Air-classified” –150 µm)
Table 3. Primary components of “ultrafines” iron ore by XRF analysis in %
Sample Al
2 O
3 Fe
2 O
3 Fe (Calculated*) SiO
2 LOI
Ultrafines Iron Ore (–10 µm) 7.7 66.0 46.2 20.8 4.3
Standard Deviation 1.0 1.5 1.0 0.7 0.7
Air-classified Iron Or (–150 µm) 2.2 59.7 41.8 36.6 1.0
Standard Deviation 0.7 1.0 0.7 0.7 0.1
*Calculated using stoichiometric relationship between Fe
2 O
3 and Fe
A design of experiment approach was used to evalu-
ate the factors (variables) that can be used to affect sepa-
ration on the STET tribo-electrostatic machine for both
“ultrafines” and “air-classified” iron ore samples. The design
was constructed using JMP software, whereby the model
included main effects, second order effects, and quadratic
interactions of continuous variables. Table 4 shows the fac-
tors and their respective levels that were tested.
Figure 2. (s) Particle size distribution by cumulative volume (“Ultrafines” –10 µm) (b) Particle size distribution by cumulative
volume (“Air-classified” –150 µm)
Table 3. Primary components of “ultrafines” iron ore by XRF analysis in %
Sample Al
2 O
3 Fe
2 O
3 Fe (Calculated*) SiO
2 LOI
Ultrafines Iron Ore (–10 µm) 7.7 66.0 46.2 20.8 4.3
Standard Deviation 1.0 1.5 1.0 0.7 0.7
Air-classified Iron Or (–150 µm) 2.2 59.7 41.8 36.6 1.0
Standard Deviation 0.7 1.0 0.7 0.7 0.1
*Calculated using stoichiometric relationship between Fe
2 O
3 and Fe