3362 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
RCs have proven to be excellent at desliming and
removing mica from pegmatite ore ahead of DMS and
flotation.
FLOTATION TO PRODUCE
CONCENTRATES
A number of things are critical for flotation concentration
of pegmatite ores:
1. Good quality water is required.
2. The ore must be deslimed ahead of flotation.
3. Reagent conditioning is required usually longer
than for sulfide ores.
4. Weathered ores exhibit poor recovery.
5. Open circuit cleaning with no recycle.
6. No tailings return water can be used without
pretreatment.
7. Fatty acid collector blends are used with soda ash
for pH control and sodium silicate as a disper-
sant. Reagent collector addition rates are 300 to
4,000 g/t.
Flotation relies on adding a collector (oleic acid) and
frother and then sparging air to cause the lithium minerals
to attach to air bubbles and float as a concentrate between
5 to 6% Li2O (Figure 6).
Fatty acid collectors can cause foaming and require
diesel to stabilise the froth. Optimising the reagents takes
time. The flotation of spodumene at plant scale (Figure 7)
is far more difficult than sulfide flotation. A lot of projects
by passed pilotting and this proved to be very costly (learn-
ing curve).
Talison spodumene flotation works very well. However,
this is a result of many years of hard work and develop-
ment. It is not typical of the new lithium projects. With the
value of hindsight, the industry approach has been far too
simplistic and optimistic and operations are now paying
for the oversights. The current new spodumene producers
took a long time to achieve design throughput. It is a huge
learning curve, (Connelly, ALTA, 2022). Some of the issues
were:
• Micaceous material
• Water quality not good enough
• Poor flotation performance in winter required slurry
heating to be retrofitted
• Mineralogy not well understood
• Fine slimes
• Waste dilution in the ore feed
• Non selective mining and blending. Campaigning
later required
• Fines/coarse characteristics in pit not recognised as
being important for processing
• Long conditioning times required (up to 30 minutes)
Figure 5. Typical Reflux Classifier (METSLibary)
Figure 6. Flotation of Lithium Concentrate (METS Libary)
RCs have proven to be excellent at desliming and
removing mica from pegmatite ore ahead of DMS and
flotation.
FLOTATION TO PRODUCE
CONCENTRATES
A number of things are critical for flotation concentration
of pegmatite ores:
1. Good quality water is required.
2. The ore must be deslimed ahead of flotation.
3. Reagent conditioning is required usually longer
than for sulfide ores.
4. Weathered ores exhibit poor recovery.
5. Open circuit cleaning with no recycle.
6. No tailings return water can be used without
pretreatment.
7. Fatty acid collector blends are used with soda ash
for pH control and sodium silicate as a disper-
sant. Reagent collector addition rates are 300 to
4,000 g/t.
Flotation relies on adding a collector (oleic acid) and
frother and then sparging air to cause the lithium minerals
to attach to air bubbles and float as a concentrate between
5 to 6% Li2O (Figure 6).
Fatty acid collectors can cause foaming and require
diesel to stabilise the froth. Optimising the reagents takes
time. The flotation of spodumene at plant scale (Figure 7)
is far more difficult than sulfide flotation. A lot of projects
by passed pilotting and this proved to be very costly (learn-
ing curve).
Talison spodumene flotation works very well. However,
this is a result of many years of hard work and develop-
ment. It is not typical of the new lithium projects. With the
value of hindsight, the industry approach has been far too
simplistic and optimistic and operations are now paying
for the oversights. The current new spodumene producers
took a long time to achieve design throughput. It is a huge
learning curve, (Connelly, ALTA, 2022). Some of the issues
were:
• Micaceous material
• Water quality not good enough
• Poor flotation performance in winter required slurry
heating to be retrofitted
• Mineralogy not well understood
• Fine slimes
• Waste dilution in the ore feed
• Non selective mining and blending. Campaigning
later required
• Fines/coarse characteristics in pit not recognised as
being important for processing
• Long conditioning times required (up to 30 minutes)
Figure 5. Typical Reflux Classifier (METSLibary)
Figure 6. Flotation of Lithium Concentrate (METS Libary)