3038 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
The Effects of Different Planetary Ball Mill Grinding
Conditions on the Flotation Separation of Molybdenite
and Talc
The flowchart of molybdenite cleaning test was shown
in Figure 4. The process of reverse flotation was used to
obtain the final molybdenite concentrate. Since the grade
of molybdenum in the obtained molybdenite concentrate
was between 38% and 42%, this work mainly focuses on
the influence of the grinding conditions on the molybde-
nite recovery. The flotation results were shown in Figure 5.
As the grinding time increases, the recovery of molybde-
nite increases, which might due to the fact that during the
grinding process, the grinding medium destroys the hydro-
phobic “face” of molybdenite and exposes more hydro-
philic “edges,” resulting in a decrease in its floatability(Lu,
Liu, Xu, &Zeng, 2015). Stainless steel balls have a higher
density and have the highest efficiency in destroying the
face surface of molybdenite, therefore, when using stainless
steel balls as grinding media, the recovery rate of molybde-
nite was maximized.
Particle size distribution of molybdenite and talc
grinding products in planetary ball mill
The particle size distribution of the ground products of
molybdenite and talc in the planetary ball mill was shown
in Figure 6. From Figure 6. (a), it could be seen that the
distribution of ground products of molybdenite had two
peaks, indicating that the comminution mechanism of
molybdenite in the planetary ball mill is mainly surface
comminution(Varinot, Hiltgun, Pons, &Dodds, 1997).
From Figure 6. (b), it could be seen that the distribution
shape of ground products of talc was unimodal, indicating
that the main comminution mechanism of talc was volume
comminution(Varinot et al., 1997).
Figure 7 was a schematic diagram of surface and vol-
ume comminution of molybdenite and talc. In the surface
comminution model, only the surface of the particle was
destroyed and micro-particles fall off, while the interior of
the particle was almost undamaged(Middlemiss, 2007). In
the volume comminution model, the entire particle was
destroyed, and the resulting product was mostly large inter-
mediate particles, which were further comminuted into fine
pH?8.5
Fe reverse flotation
Fe concentrate
Grinding fineness -0.038 mm 77%
Mo Pre cleaner
Mo
Mo
Mo Middling
Tailing
Mo Pre cleaner concentrate
CaO 2000
Waterglass 4000+ (NaPO3)6 1000
Diesel oil 80
MIBC 50
Waterglass 2000+(NaPO3)6 500
Waterglass 1000+(NaPO3)6 300
Waterglass 500+(NaPO3)6 150
Rougher concentrate
Reagent dosage: g/t
(relative to rougher concentrate)
Figure 3. Pre flotation test process of the rougher concentrate
The Effects of Different Planetary Ball Mill Grinding
Conditions on the Flotation Separation of Molybdenite
and Talc
The flowchart of molybdenite cleaning test was shown
in Figure 4. The process of reverse flotation was used to
obtain the final molybdenite concentrate. Since the grade
of molybdenum in the obtained molybdenite concentrate
was between 38% and 42%, this work mainly focuses on
the influence of the grinding conditions on the molybde-
nite recovery. The flotation results were shown in Figure 5.
As the grinding time increases, the recovery of molybde-
nite increases, which might due to the fact that during the
grinding process, the grinding medium destroys the hydro-
phobic “face” of molybdenite and exposes more hydro-
philic “edges,” resulting in a decrease in its floatability(Lu,
Liu, Xu, &Zeng, 2015). Stainless steel balls have a higher
density and have the highest efficiency in destroying the
face surface of molybdenite, therefore, when using stainless
steel balls as grinding media, the recovery rate of molybde-
nite was maximized.
Particle size distribution of molybdenite and talc
grinding products in planetary ball mill
The particle size distribution of the ground products of
molybdenite and talc in the planetary ball mill was shown
in Figure 6. From Figure 6. (a), it could be seen that the
distribution of ground products of molybdenite had two
peaks, indicating that the comminution mechanism of
molybdenite in the planetary ball mill is mainly surface
comminution(Varinot, Hiltgun, Pons, &Dodds, 1997).
From Figure 6. (b), it could be seen that the distribution
shape of ground products of talc was unimodal, indicating
that the main comminution mechanism of talc was volume
comminution(Varinot et al., 1997).
Figure 7 was a schematic diagram of surface and vol-
ume comminution of molybdenite and talc. In the surface
comminution model, only the surface of the particle was
destroyed and micro-particles fall off, while the interior of
the particle was almost undamaged(Middlemiss, 2007). In
the volume comminution model, the entire particle was
destroyed, and the resulting product was mostly large inter-
mediate particles, which were further comminuted into fine
pH?8.5
Fe reverse flotation
Fe concentrate
Grinding fineness -0.038 mm 77%
Mo Pre cleaner
Mo
Mo
Mo Middling
Tailing
Mo Pre cleaner concentrate
CaO 2000
Waterglass 4000+ (NaPO3)6 1000
Diesel oil 80
MIBC 50
Waterglass 2000+(NaPO3)6 500
Waterglass 1000+(NaPO3)6 300
Waterglass 500+(NaPO3)6 150
Rougher concentrate
Reagent dosage: g/t
(relative to rougher concentrate)
Figure 3. Pre flotation test process of the rougher concentrate