1958 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
METHODOLOGY
The Wet High Intensity Magnetic Separator (WHIMS)
of the Jones type is widely employed in iron mining, uti-
lized since the 1970s by major industry players such as Vale
(Silva 2012).
The equipment consists of a magnetic circuit composed
of poles and rotors. Electromagnetic coils, inducing the
magnetic field of the magnetic separator, are mounted on
the poles. On the rotors (sometimes referred to as the “hori-
zontal ring” or carousel), magnetic matrices are installed,
the element where magnetic separation or concentration
occurs. The rotors are mounted on a shaft and drive sys-
tem that allows their rotation. Through this rotation, the
matrices are placed in front of the poles, which, under the
influence of the magnetic field generated by the coils, mag-
netize the magnetic matrices. At this point, the pulp is fed
into these matrices. At this moment, magnetic particles are
attracted and trapped within the magnetic matrices. Non-
magnetic or weakly magnetic particles are carried away by
water and collected just below the matrices in the tray for
collecting non-magnetic products (or tailings in the case
of iron ore concentration). With the constant rotation, the
matrices containing the magnetic material move in front of
the pole to the region where a wash spray of middlings is
applied. At this point, any non-magnetic particles trapped
in the matrices are washed out of the matrices and collected
in the tray for collecting middlings products. Finally, the
rotor’s rotation guides the matrices containing the magnetic
minerals to the equipment’s region outside the influence of
the magnetic field, where a spray is applied for discharging
the magnetic material (or concentrate in the case of iron ore
concentration). This material is collected in the magnetic
product tray, and the matrices are cleaned to receive new
feed at the next pole (Figure 1).
In this equipment, concentration occurs through the
competition between the vertical force of hydraulic drag
acting on all particles and the magnetic attractive force act-
ing on magnetizable particles.
The equation (Svoboda, 2004) defining the magnetic
attractive force is given by:
F
d x · ·B ·dB
m
0
3
n =
d =Particle Diameter
xm =Ore Susceptibility
B =Magnetic Field
B d =Magnetic Field Gradient
o n =Permeability of Vacuum
It can be observed that the smaller the diameter of the par-
ticles, the smaller the attractive force, and therefore, the
Figure 1. Components of the Jones-type magnetic separator
METHODOLOGY
The Wet High Intensity Magnetic Separator (WHIMS)
of the Jones type is widely employed in iron mining, uti-
lized since the 1970s by major industry players such as Vale
(Silva 2012).
The equipment consists of a magnetic circuit composed
of poles and rotors. Electromagnetic coils, inducing the
magnetic field of the magnetic separator, are mounted on
the poles. On the rotors (sometimes referred to as the “hori-
zontal ring” or carousel), magnetic matrices are installed,
the element where magnetic separation or concentration
occurs. The rotors are mounted on a shaft and drive sys-
tem that allows their rotation. Through this rotation, the
matrices are placed in front of the poles, which, under the
influence of the magnetic field generated by the coils, mag-
netize the magnetic matrices. At this point, the pulp is fed
into these matrices. At this moment, magnetic particles are
attracted and trapped within the magnetic matrices. Non-
magnetic or weakly magnetic particles are carried away by
water and collected just below the matrices in the tray for
collecting non-magnetic products (or tailings in the case
of iron ore concentration). With the constant rotation, the
matrices containing the magnetic material move in front of
the pole to the region where a wash spray of middlings is
applied. At this point, any non-magnetic particles trapped
in the matrices are washed out of the matrices and collected
in the tray for collecting middlings products. Finally, the
rotor’s rotation guides the matrices containing the magnetic
minerals to the equipment’s region outside the influence of
the magnetic field, where a spray is applied for discharging
the magnetic material (or concentrate in the case of iron ore
concentration). This material is collected in the magnetic
product tray, and the matrices are cleaned to receive new
feed at the next pole (Figure 1).
In this equipment, concentration occurs through the
competition between the vertical force of hydraulic drag
acting on all particles and the magnetic attractive force act-
ing on magnetizable particles.
The equation (Svoboda, 2004) defining the magnetic
attractive force is given by:
F
d x · ·B ·dB
m
0
3
n =
d =Particle Diameter
xm =Ore Susceptibility
B =Magnetic Field
B d =Magnetic Field Gradient
o n =Permeability of Vacuum
It can be observed that the smaller the diameter of the par-
ticles, the smaller the attractive force, and therefore, the
Figure 1. Components of the Jones-type magnetic separator