XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3523
of 29.4%. The inclusion of the frother thus proved benefi-
cial to the system, leading to a modest improvement in sul-
phur recovery. The total sulphur values analyzed in the test
products include sulphate minerals found in the Cantung
tailings. It is important to note that primary sulphide min-
erals are well-known contributors to acid rock drainage
due to their potential to oxidize and form sulphuric acid.
While certain secondary sulphate minerals such as gypsum
and alunite form as a result of these processes and may not
directly generate acid, their presence in mine waste envi-
ronments can influence the geochemical stability and may
indirectly contribute to ongoing acidity through complex
geochemical interactions. As can be seen in Table 7, the
experiment CTOP-4 resulted in a lower sulphur that con-
tributes to acid mine drainage.
The tailings of flotation test CTOP-4 were passed
through the Falcon concentrator and the Falcon concen-
trate was used for leaching as shown in the flowsheet dia-
gram in Figure 8. The results of the Falcon concentrator test
performed using flotation tailings as feed are summarized in
Table 8 and Table 9. The cumulative tungsten grade of the
Falcon concentrate was 0.50% at a unit recovery of 79.2%.
The upgrade ratio was about two times (from 0.28% to
0.50% tungsten) at a mass pull of 43.7% reducing the feed
mass (and operation costs) in the tungsten leaching circuit.
The comparison between caustic soda atmospheric
leaching and caustic soda mechanochemical leaching
revealed an enhancement in tungsten extraction levels
using the mechanochemical method. After just one hour
of retention time, the extraction levels improved up to
four times, reaching above 60% W. This improvement can
be attributed to the heightened reactivity of the mineral
being leached, a consequence of increased internal and sur-
face energy, expanded surface area, and reduced coherence
energy. High-energy mills achieve mechanical activation
through impact, attrition, and compression. Simultaneous
grinding and leaching enhance the reactivity of solid min-
eral particles, mechanically activating scheelite. The explo-
ration of this specific aspect of our study is still in its nascent
stages, and a comprehensive discussion surpassing will be
explored in detail in a future article.
CONCLUSION
The primary objective of this study was to recover valuable
metals, specifically tungsten and copper, from historical
tailings at the Cantung mine. Various mineral processing
techniques, including gravity separation, magnetic separa-
tion, and flotation, were explored to achieve optimal min-
eral recovery. A critical focus of the study was to mitigate
the environmental impact of historical tailings, particularly
Table 8. Cumulative grade of falcon concentrator test using flotation tailings as feed
Stream Mass Pull, %W, %Cu, %Fe, %S, %
Falcon Conc. 1 7.30 0.83 0.042 11.27 2.38
Falcon Conc. 2 15.1 0.68 0.039 10.78 2.18
Falcon Conc. 3 20.8 0.64 0.038 10.69 2.14
Falcon Conc. 4 25.8 0.62 0.038 10.54 2.08
Falcon Conc. 5 30.9 0.58 0.037 10.48 2.02
Falcon Conc. 6 30.3 0.53 0.034 10.26 1.89
Falcon Conc. 7 43.7 0.50 0.033 10.17 1.85
Falcon Tailing 100 0.10 0.023 8.40 0.96
Table 9. Cumulative recovery of falcon concentrator test using flotation tailings as feed
Stream Mass Pull, %W, %Cu, %Fe, %S, %
Falcon Conc. 1 7.30 21.85 11.18 8.960 12.88
Falcon Conc. 2 15.1 36.78 21.33 17.75 24.41
Falcon Conc. 3 20.8 48.07 28.72 24.19 32.94
Falcon Conc. 4 25.8 57.85 35.38 29.66 39.80
Falcon Conc. 5 30.9 64.85 41.19 35.26 46.25
Falcon Conc. 6 30.3 74.74 48.82 43.97 55.14
Falcon Conc. 7 43.7 79.17 53.39 48.49 59.93
Falcon Tailing 100 100.0 100.0 100.0 100.0
of 29.4%. The inclusion of the frother thus proved benefi-
cial to the system, leading to a modest improvement in sul-
phur recovery. The total sulphur values analyzed in the test
products include sulphate minerals found in the Cantung
tailings. It is important to note that primary sulphide min-
erals are well-known contributors to acid rock drainage
due to their potential to oxidize and form sulphuric acid.
While certain secondary sulphate minerals such as gypsum
and alunite form as a result of these processes and may not
directly generate acid, their presence in mine waste envi-
ronments can influence the geochemical stability and may
indirectly contribute to ongoing acidity through complex
geochemical interactions. As can be seen in Table 7, the
experiment CTOP-4 resulted in a lower sulphur that con-
tributes to acid mine drainage.
The tailings of flotation test CTOP-4 were passed
through the Falcon concentrator and the Falcon concen-
trate was used for leaching as shown in the flowsheet dia-
gram in Figure 8. The results of the Falcon concentrator test
performed using flotation tailings as feed are summarized in
Table 8 and Table 9. The cumulative tungsten grade of the
Falcon concentrate was 0.50% at a unit recovery of 79.2%.
The upgrade ratio was about two times (from 0.28% to
0.50% tungsten) at a mass pull of 43.7% reducing the feed
mass (and operation costs) in the tungsten leaching circuit.
The comparison between caustic soda atmospheric
leaching and caustic soda mechanochemical leaching
revealed an enhancement in tungsten extraction levels
using the mechanochemical method. After just one hour
of retention time, the extraction levels improved up to
four times, reaching above 60% W. This improvement can
be attributed to the heightened reactivity of the mineral
being leached, a consequence of increased internal and sur-
face energy, expanded surface area, and reduced coherence
energy. High-energy mills achieve mechanical activation
through impact, attrition, and compression. Simultaneous
grinding and leaching enhance the reactivity of solid min-
eral particles, mechanically activating scheelite. The explo-
ration of this specific aspect of our study is still in its nascent
stages, and a comprehensive discussion surpassing will be
explored in detail in a future article.
CONCLUSION
The primary objective of this study was to recover valuable
metals, specifically tungsten and copper, from historical
tailings at the Cantung mine. Various mineral processing
techniques, including gravity separation, magnetic separa-
tion, and flotation, were explored to achieve optimal min-
eral recovery. A critical focus of the study was to mitigate
the environmental impact of historical tailings, particularly
Table 8. Cumulative grade of falcon concentrator test using flotation tailings as feed
Stream Mass Pull, %W, %Cu, %Fe, %S, %
Falcon Conc. 1 7.30 0.83 0.042 11.27 2.38
Falcon Conc. 2 15.1 0.68 0.039 10.78 2.18
Falcon Conc. 3 20.8 0.64 0.038 10.69 2.14
Falcon Conc. 4 25.8 0.62 0.038 10.54 2.08
Falcon Conc. 5 30.9 0.58 0.037 10.48 2.02
Falcon Conc. 6 30.3 0.53 0.034 10.26 1.89
Falcon Conc. 7 43.7 0.50 0.033 10.17 1.85
Falcon Tailing 100 0.10 0.023 8.40 0.96
Table 9. Cumulative recovery of falcon concentrator test using flotation tailings as feed
Stream Mass Pull, %W, %Cu, %Fe, %S, %
Falcon Conc. 1 7.30 21.85 11.18 8.960 12.88
Falcon Conc. 2 15.1 36.78 21.33 17.75 24.41
Falcon Conc. 3 20.8 48.07 28.72 24.19 32.94
Falcon Conc. 4 25.8 57.85 35.38 29.66 39.80
Falcon Conc. 5 30.9 64.85 41.19 35.26 46.25
Falcon Conc. 6 30.3 74.74 48.82 43.97 55.14
Falcon Conc. 7 43.7 79.17 53.39 48.49 59.93
Falcon Tailing 100 100.0 100.0 100.0 100.0