XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2661
was maintained at 7.8 using soda ash (Na2CO3) and sulph-
uric acid (H2SO4). Collectors were added stepwise (600g/t
+300g/t +300g/t) during the rougher flotation stage. Pulp
density was set at 30% w/w, conditioning was done for 15
mins (1st dose) at an agitator speed of 1,200 rpm. At each
subsequent collector addition point the conditioning was
then done for 10 mins. Flotation was carried out at an air
rate of 7L/min for 16 min at an impeller speed of 1,000
rpm. In multistage flotation, the rougher concentrates were
combined and used as feed for the cleaner stage. The clean-
ing was done for 6 mins with the agitator set at 1,000 rpm
without adding any collectors. The cleaner concentrate was
further cleaned in a re-cleaner flotation with the impeller
speed set at 900 rpm while the air flow rate was set at 4L/
min. Flotation was carried out for 8 mins.
Reverse Spodumene Flotation (mica pre flotation)
Figure 1 shows the general flow sheet that was used to
study mica flotation with a fatty amine before spodumene
flotation. The same flow diagram was used with the alkyl-
esteramine (Armoflote 945 product) with the exception
that the collector was added as a single dose (75g/t) in the
rougher and flotation was continued for 8 mins. The pro-
cess involved adding a 600g sample of the ore (Sample B)
to a 2L flotation cell to make 25% w/w pulp density. The
tests were done using an Outotec GTK LabCell ™ flota-
tion machine operated at 1,000rpm during conditioning
and 800rpm during flotation. The pH of the pulp was
maintained at 8 using soda ash and sulphuric acid. Dextrin
yellow at 1,000g/t was dosed in the rougher and condi-
tioned as shown in Table 3. All reagents were added as 1%
Table 1. Composition of the ore (direct Spodumene flotation)- Sample A
Li
2 O, ppm Fe, %Al
2 O
3, %SiO
2, %TiO
2, %Mn, %S, %P, %SnO
2 ,%
13,380 2.02 15.44 70.87 0.013 0.171 0.079 0.052 0.028
Ta2O5, %Nb2O5, %Na2O, %PbO,% CaO %MgO %K2O %Rb ppm LOI1000 %
0.013 0.002 3.5 0.008 0.48 0.38 3.024 4998 0.8
Table 2. Composition of the ore (Mica preflot)- Sample B
Li2O, ppm Fe2O3, %Al2O3, %SiO2, %TiO2, %Mn, %S, %P, %SnO2, %
12,520 0.267 16.09 75.08 0.008 0.029 0.001 0.131 0.006
Ta
2 O
5 ,%Nb
2 O
5 ,%Na
2 O, %PbO, %CaO, %MgO, %K
2 O, %Rb, ppm LOI
1000 ,%
0.002 0.002 3.525 0.002 0.188 0.0421 2.405 555 0.96
Figure 1. Spodumene reverse flotation flow diagram
was maintained at 7.8 using soda ash (Na2CO3) and sulph-
uric acid (H2SO4). Collectors were added stepwise (600g/t
+300g/t +300g/t) during the rougher flotation stage. Pulp
density was set at 30% w/w, conditioning was done for 15
mins (1st dose) at an agitator speed of 1,200 rpm. At each
subsequent collector addition point the conditioning was
then done for 10 mins. Flotation was carried out at an air
rate of 7L/min for 16 min at an impeller speed of 1,000
rpm. In multistage flotation, the rougher concentrates were
combined and used as feed for the cleaner stage. The clean-
ing was done for 6 mins with the agitator set at 1,000 rpm
without adding any collectors. The cleaner concentrate was
further cleaned in a re-cleaner flotation with the impeller
speed set at 900 rpm while the air flow rate was set at 4L/
min. Flotation was carried out for 8 mins.
Reverse Spodumene Flotation (mica pre flotation)
Figure 1 shows the general flow sheet that was used to
study mica flotation with a fatty amine before spodumene
flotation. The same flow diagram was used with the alkyl-
esteramine (Armoflote 945 product) with the exception
that the collector was added as a single dose (75g/t) in the
rougher and flotation was continued for 8 mins. The pro-
cess involved adding a 600g sample of the ore (Sample B)
to a 2L flotation cell to make 25% w/w pulp density. The
tests were done using an Outotec GTK LabCell ™ flota-
tion machine operated at 1,000rpm during conditioning
and 800rpm during flotation. The pH of the pulp was
maintained at 8 using soda ash and sulphuric acid. Dextrin
yellow at 1,000g/t was dosed in the rougher and condi-
tioned as shown in Table 3. All reagents were added as 1%
Table 1. Composition of the ore (direct Spodumene flotation)- Sample A
Li
2 O, ppm Fe, %Al
2 O
3, %SiO
2, %TiO
2, %Mn, %S, %P, %SnO
2 ,%
13,380 2.02 15.44 70.87 0.013 0.171 0.079 0.052 0.028
Ta2O5, %Nb2O5, %Na2O, %PbO,% CaO %MgO %K2O %Rb ppm LOI1000 %
0.013 0.002 3.5 0.008 0.48 0.38 3.024 4998 0.8
Table 2. Composition of the ore (Mica preflot)- Sample B
Li2O, ppm Fe2O3, %Al2O3, %SiO2, %TiO2, %Mn, %S, %P, %SnO2, %
12,520 0.267 16.09 75.08 0.008 0.029 0.001 0.131 0.006
Ta
2 O
5 ,%Nb
2 O
5 ,%Na
2 O, %PbO, %CaO, %MgO, %K
2 O, %Rb, ppm LOI
1000 ,%
0.002 0.002 3.525 0.002 0.188 0.0421 2.405 555 0.96
Figure 1. Spodumene reverse flotation flow diagram