XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2649
minor abundance of cassiterite, columbite, tantalite, micro-
lite and phosphate (refs). The objective of this study is the
recovery of lepidolite.
Comminution
Prior pilot grinding test, the sample was submitted to jaw,
gyratory and roll crushers to provide a particle size distribu-
tion suitable for ball milling (i.e., 2 mm). The pilot ball
mill and the grinding flowsheet is displayed in Figure 1.
The sample was dried feed on 280µm screen with a
flow of about 50kg/h. The passing particles are stocked in
a thickener and the retained particles are feed in the ball
mill with a solid ratio of about 60%. The ball mill has an
internal diameter of about 40cm for a length of 73cm. It
is filled with 153 kg of balls with a maximum diameter of
6cm (which represents about 22% of the full volume of
the cylinder). The rotation of the ball mill is about 40 rpm
(which stands for 60% of the critical speed). The output of
the mill is sent back to the screen using a centrifugal pump.
The pilot is finished when the whole sample is recovered in
the thickener.
Desliming
Procedure
For the purpose of the study, 3 different desliming sizes were
testes, namely 10, 40 and 63 µm. The first desliming size is
achieved using a Mosley 2 inch hydrocylone equipped with
a 14 mm vortex finder and a 3 mm spigot. The pressure
during cyloning test was kept at about 40 psi and the solid
ratio at about 2%. Other samples were deslimed using wet
sieving with test sieves of 40 and 63µm respectively.
Partition Curve
The effective cut-off size of the desliming stage is assessed by
computing the partition curve of each test. It is done by cal-
culated the probability of a particle to pass to the overflow.
Table 1. Geochemistry of the sample, Demeusy et al., 2023
Li
2 O, %Sn, ppm Nb, ppm Ta, ppm SiO
2 ,%Al
2 O
3 ,%K
2 O, %P
2 O
5 ,%
0.89 1073 106 155 68.1 17.2 3.5 0.9
Figure 1. Flowsheet of the pilot comminution test
minor abundance of cassiterite, columbite, tantalite, micro-
lite and phosphate (refs). The objective of this study is the
recovery of lepidolite.
Comminution
Prior pilot grinding test, the sample was submitted to jaw,
gyratory and roll crushers to provide a particle size distribu-
tion suitable for ball milling (i.e., 2 mm). The pilot ball
mill and the grinding flowsheet is displayed in Figure 1.
The sample was dried feed on 280µm screen with a
flow of about 50kg/h. The passing particles are stocked in
a thickener and the retained particles are feed in the ball
mill with a solid ratio of about 60%. The ball mill has an
internal diameter of about 40cm for a length of 73cm. It
is filled with 153 kg of balls with a maximum diameter of
6cm (which represents about 22% of the full volume of
the cylinder). The rotation of the ball mill is about 40 rpm
(which stands for 60% of the critical speed). The output of
the mill is sent back to the screen using a centrifugal pump.
The pilot is finished when the whole sample is recovered in
the thickener.
Desliming
Procedure
For the purpose of the study, 3 different desliming sizes were
testes, namely 10, 40 and 63 µm. The first desliming size is
achieved using a Mosley 2 inch hydrocylone equipped with
a 14 mm vortex finder and a 3 mm spigot. The pressure
during cyloning test was kept at about 40 psi and the solid
ratio at about 2%. Other samples were deslimed using wet
sieving with test sieves of 40 and 63µm respectively.
Partition Curve
The effective cut-off size of the desliming stage is assessed by
computing the partition curve of each test. It is done by cal-
culated the probability of a particle to pass to the overflow.
Table 1. Geochemistry of the sample, Demeusy et al., 2023
Li
2 O, %Sn, ppm Nb, ppm Ta, ppm SiO
2 ,%Al
2 O
3 ,%K
2 O, %P
2 O
5 ,%
0.89 1073 106 155 68.1 17.2 3.5 0.9
Figure 1. Flowsheet of the pilot comminution test