3322 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
PAN content was increased. Although not shown here, a
similar trend to Figure 6b was observed when comparing
the ratio of abietic acid to total rosin content. Since abietic
acid represented the largest portion of the PAN number for
all collectors, it is possible this species is driving the differ-
ence in iron versus lithium recovery, but further investiga-
tion is required.
The overall results showed that both rosin acid content
and composition influenced flotation performance. While
the total rosin content and addition of different rosin spe-
cies decreased the overall selectivity of the TOFA collectors,
NCY had more influence on iron performance and HYR
had a larger influence on general gangue recovery. The pro-
portion of abietic acid (or relative PAN number) preferen-
tially increased the recovery of iron recovery compared to
lithium (although the mechanism remains unclear), while
the relative concentration of dehydroabietic acid increased
overall silicate gangue mineral recovery. The general differ-
ence in flotation performance observed with the FA1 and
FA2 TOR blends requires further investigation, if the rosin
species compete or interfere with one another as suggested
by the results, it is possible the higher ratio of PAN species
in the FA2 blends led to higher overall gangue recovery.
To confirm these observations, studies investigating the col-
lector adsorption mechanism should be performed to help
identify if and how the TOR composition – like the differ-
ent PAN (or abietic acid) and dehydroabietic acid contents
– influence selective collector adsorption.
CONCLUSIONS
There is a need to better understand and improve selectiv-
ity in spodumene flotation with tall oil fatty acid collectors.
This study evaluated the impact of six different TOFA
based collectors with different rosin acid content and com-
position. The findings confirmed that FA2, with the low-
est rosin content, provided the best flotation performance.
Additionally, the relationship between iron and lithium
recoveries highlighted that rejecting iron-bearing miner-
als while maintaining high lithium recovery remains a
major challenge in spodumene flotation with fatty acids.
This study confirmed that overall rosin acid content had a
negative impact on selectivity the magnitude of the impact
differed depending on the composition of the rosin acid
impurities. The addition of the NCY tall oil rosin prefer-
entially increased iron recovery in comparison to the recov-
ery of lithium, potassium, and sodium. This implies that
the higher PAN number and abietic acid content in NCY
may have increased collector adsorption onto iron-bearing
gangue minerals. Meanwhile, the addition of HYR tall oil
rosin had a larger negative impact on overall selectivity
and increased recovery of all metals, implying that higher
dehydroabietic acid content resulted in bulk gangue min-
eral recovery (i.e., no bias towards iron or silicate gangue
minerals). Finally, the difference observed in performance
with the FA1 and FA2 blends suggested that the overall
rosin composition – not just the total rosin content – may
influence selectivity. Additional investigation is required to
better identify how the different rosin species – and poten-
tially the role of flotation pH – influence collector adsorp-
tion and flotation performance. Overall, the results help
identify which rosin species are problematic for selective
spodumene flotation and reiterate that rosin acid content
in TOFA collectors is an important consideration in col-
lector design.
4
6
8
10
12
14
16
18
20
0 0.05 0.1 0.15 0.2 0.25
Dehydroabietic Acid:Total Rosin Content
Potassium Sodium
6a.
90
91
92
93
94
95
96
97
98
99
100
65
66
67
68
69
70
71
72
73
74
75
0 0.1 0.2 0.3 0.4 0.5
PAN:Total Rosin Content
Iron Lithium
6b.
Figure 6. Ratio of (a) dehydroabietic acid to total rosin content vs. potassium and sodium recovery and (b.) PAN number to
total rosin content vs. iron recovery
K/Na
Recovery
(%)
Lithium
Recovery
(%)
Iron
Recovery
(%)
PAN content was increased. Although not shown here, a
similar trend to Figure 6b was observed when comparing
the ratio of abietic acid to total rosin content. Since abietic
acid represented the largest portion of the PAN number for
all collectors, it is possible this species is driving the differ-
ence in iron versus lithium recovery, but further investiga-
tion is required.
The overall results showed that both rosin acid content
and composition influenced flotation performance. While
the total rosin content and addition of different rosin spe-
cies decreased the overall selectivity of the TOFA collectors,
NCY had more influence on iron performance and HYR
had a larger influence on general gangue recovery. The pro-
portion of abietic acid (or relative PAN number) preferen-
tially increased the recovery of iron recovery compared to
lithium (although the mechanism remains unclear), while
the relative concentration of dehydroabietic acid increased
overall silicate gangue mineral recovery. The general differ-
ence in flotation performance observed with the FA1 and
FA2 TOR blends requires further investigation, if the rosin
species compete or interfere with one another as suggested
by the results, it is possible the higher ratio of PAN species
in the FA2 blends led to higher overall gangue recovery.
To confirm these observations, studies investigating the col-
lector adsorption mechanism should be performed to help
identify if and how the TOR composition – like the differ-
ent PAN (or abietic acid) and dehydroabietic acid contents
– influence selective collector adsorption.
CONCLUSIONS
There is a need to better understand and improve selectiv-
ity in spodumene flotation with tall oil fatty acid collectors.
This study evaluated the impact of six different TOFA
based collectors with different rosin acid content and com-
position. The findings confirmed that FA2, with the low-
est rosin content, provided the best flotation performance.
Additionally, the relationship between iron and lithium
recoveries highlighted that rejecting iron-bearing miner-
als while maintaining high lithium recovery remains a
major challenge in spodumene flotation with fatty acids.
This study confirmed that overall rosin acid content had a
negative impact on selectivity the magnitude of the impact
differed depending on the composition of the rosin acid
impurities. The addition of the NCY tall oil rosin prefer-
entially increased iron recovery in comparison to the recov-
ery of lithium, potassium, and sodium. This implies that
the higher PAN number and abietic acid content in NCY
may have increased collector adsorption onto iron-bearing
gangue minerals. Meanwhile, the addition of HYR tall oil
rosin had a larger negative impact on overall selectivity
and increased recovery of all metals, implying that higher
dehydroabietic acid content resulted in bulk gangue min-
eral recovery (i.e., no bias towards iron or silicate gangue
minerals). Finally, the difference observed in performance
with the FA1 and FA2 blends suggested that the overall
rosin composition – not just the total rosin content – may
influence selectivity. Additional investigation is required to
better identify how the different rosin species – and poten-
tially the role of flotation pH – influence collector adsorp-
tion and flotation performance. Overall, the results help
identify which rosin species are problematic for selective
spodumene flotation and reiterate that rosin acid content
in TOFA collectors is an important consideration in col-
lector design.
4
6
8
10
12
14
16
18
20
0 0.05 0.1 0.15 0.2 0.25
Dehydroabietic Acid:Total Rosin Content
Potassium Sodium
6a.
90
91
92
93
94
95
96
97
98
99
100
65
66
67
68
69
70
71
72
73
74
75
0 0.1 0.2 0.3 0.4 0.5
PAN:Total Rosin Content
Iron Lithium
6b.
Figure 6. Ratio of (a) dehydroabietic acid to total rosin content vs. potassium and sodium recovery and (b.) PAN number to
total rosin content vs. iron recovery
K/Na
Recovery
(%)
Lithium
Recovery
(%)
Iron
Recovery
(%)