1230 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
Wilfley Table Separation
Although not being considered as a competing technology
to WHIMS or flotation, given the likely large scale of the
Halleck Creek operation and limited capacity of industrial
gravity concentration units, exploratory Wilfley table test-
ing was undertaken as a means of generating concentrate
of similar composition to WHIMS magnetics, comprising
a majority of Fe amphiboles, residual feldspars/silica and
allanite. Concentrate produced from this work was used for
downstream hydrometallurgical testwork.
Sub-samples of crushed ore were milled to a P80 of
250 µm and split into three fractions to improve mineral
separation: +250 µm, 75 to 250 µm and minus 75 µm.
Each fraction was subjected to tabling, producing four to
six concentrates and one tail. Results of fractionated tabling
are presented as Table 3.
The Wilfley table was more effective than WHIMS
in rejecting Fe but REO recovery suffered, primarily due
to losses in the minus 75 µm fraction. Gravity separa-
tion also did not produce as high a TREO+Y concentrate
grade, though the P80 grind size was slightly coarse than the
cleaner WHIMS (250 versus 106 µm).
Centrifugal Separation
The Wilfley table test outcome in terms of Fe rejec-
tion was sufficiently promising to justify undertaking
a Falcon C proxy test using a batch SB-6 test unit fitted
with a non-fluidised bowl. A 5 kg sub-sample of cleaner
Figure 9. Cleaner WHIMS magnetics HLS sinks grade by SG partition
Table 3. Wilfley table gravity concentration test summary
Product
Mass TREO +Y Fe
2 O
3 SiO
2 Al
2 O
3
%%%dist %%dist %%dist %%dist
Feed 100.0 0.43 100.0 7.65 100.0 61.2 100.0 15.3 100.0
+250 um, Cons 1 and 2 17.2 0.57 22.5 10.4 23.4 60.5 17.1 14.7 16.6
75 to 250 um, Cons 1 to 3 16.6 0.89 34.0 16.4 35.5 54.9 14.9 12.8 13.8
–75 um, Cons 1 to 3 1.4 1.25 4.1 24.4 4.5 45.5 1.1 10.3 0.9
Combined—selected cons 35.2 0.75 60.5 13.8 63.4 57.3 33.0 13.6 31.4
Cleaner WHIMS Magnetics 16.1 1.51 69.2 34.3 78.4 39.9 10.3 8.46 8.6
Wilfley Table Separation
Although not being considered as a competing technology
to WHIMS or flotation, given the likely large scale of the
Halleck Creek operation and limited capacity of industrial
gravity concentration units, exploratory Wilfley table test-
ing was undertaken as a means of generating concentrate
of similar composition to WHIMS magnetics, comprising
a majority of Fe amphiboles, residual feldspars/silica and
allanite. Concentrate produced from this work was used for
downstream hydrometallurgical testwork.
Sub-samples of crushed ore were milled to a P80 of
250 µm and split into three fractions to improve mineral
separation: +250 µm, 75 to 250 µm and minus 75 µm.
Each fraction was subjected to tabling, producing four to
six concentrates and one tail. Results of fractionated tabling
are presented as Table 3.
The Wilfley table was more effective than WHIMS
in rejecting Fe but REO recovery suffered, primarily due
to losses in the minus 75 µm fraction. Gravity separa-
tion also did not produce as high a TREO+Y concentrate
grade, though the P80 grind size was slightly coarse than the
cleaner WHIMS (250 versus 106 µm).
Centrifugal Separation
The Wilfley table test outcome in terms of Fe rejec-
tion was sufficiently promising to justify undertaking
a Falcon C proxy test using a batch SB-6 test unit fitted
with a non-fluidised bowl. A 5 kg sub-sample of cleaner
Figure 9. Cleaner WHIMS magnetics HLS sinks grade by SG partition
Table 3. Wilfley table gravity concentration test summary
Product
Mass TREO +Y Fe
2 O
3 SiO
2 Al
2 O
3
%%%dist %%dist %%dist %%dist
Feed 100.0 0.43 100.0 7.65 100.0 61.2 100.0 15.3 100.0
+250 um, Cons 1 and 2 17.2 0.57 22.5 10.4 23.4 60.5 17.1 14.7 16.6
75 to 250 um, Cons 1 to 3 16.6 0.89 34.0 16.4 35.5 54.9 14.9 12.8 13.8
–75 um, Cons 1 to 3 1.4 1.25 4.1 24.4 4.5 45.5 1.1 10.3 0.9
Combined—selected cons 35.2 0.75 60.5 13.8 63.4 57.3 33.0 13.6 31.4
Cleaner WHIMS Magnetics 16.1 1.51 69.2 34.3 78.4 39.9 10.3 8.46 8.6