XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2067
and silica is marginal, with finer silica particles accumulat-
ing more prominently in this zone. Moving to the inter-
mediate zones (zone 2 and zone 3), the width of the size
distribution curves increases significantly, signifying more
substantial zones to separate magnetite and silica particles.
The outer zones (zone 4 and zone 5), represent the tail-
ings, the width is relatively smaller than in the intermediate
zones but larger compared to the inner zone. This suggests
moderate separation in the outer zones, with accumulation
of most of the fines. It is observed that the width of curves
in zone 4 is broader for the 20 :80 mixture compared to the
50: 50 mixture, indicating a notable improvement in sepa-
ration efficiency in zone 4 due to changes in feed composi-
tion. Interactions become more prominent with increased
silica, impacting settling and separation across the zones.
The average sizes and the width of size distribution curves
highlight the complex interplay of forces in the spiral con-
centrator and the efficiency of separation for different feed
compositions. The intermediate zones (zone 2 and zone 3)
exhibit more effective separation for the bicomponent par-
ticles in the spiral concentrator.
In the feed mixture of 80% silica (zone 1), where sil-
ica constitutes the majority, the average size of magnetite
is 39.35 µm. In the feed mixture of 50% silica, the bal-
anced composition leads to a reduced magnetite average
size of 44.82 µm in zone 1 (Figure 7). Finally, in the pure
magnetite mixture, where the feed is entirely magnetite,
the average size further decreases to 39.49 µm in zone 1.
Figure 5. Comparison of mean particle size distributions of a) magnetite and b) silica of pure feed in separation zones
Figure 6. Comparison of mean particle size distributions of magnetite and silica in feed proportions of a) 20: 80 b) 50:50 in
separation zones
and silica is marginal, with finer silica particles accumulat-
ing more prominently in this zone. Moving to the inter-
mediate zones (zone 2 and zone 3), the width of the size
distribution curves increases significantly, signifying more
substantial zones to separate magnetite and silica particles.
The outer zones (zone 4 and zone 5), represent the tail-
ings, the width is relatively smaller than in the intermediate
zones but larger compared to the inner zone. This suggests
moderate separation in the outer zones, with accumulation
of most of the fines. It is observed that the width of curves
in zone 4 is broader for the 20 :80 mixture compared to the
50: 50 mixture, indicating a notable improvement in sepa-
ration efficiency in zone 4 due to changes in feed composi-
tion. Interactions become more prominent with increased
silica, impacting settling and separation across the zones.
The average sizes and the width of size distribution curves
highlight the complex interplay of forces in the spiral con-
centrator and the efficiency of separation for different feed
compositions. The intermediate zones (zone 2 and zone 3)
exhibit more effective separation for the bicomponent par-
ticles in the spiral concentrator.
In the feed mixture of 80% silica (zone 1), where sil-
ica constitutes the majority, the average size of magnetite
is 39.35 µm. In the feed mixture of 50% silica, the bal-
anced composition leads to a reduced magnetite average
size of 44.82 µm in zone 1 (Figure 7). Finally, in the pure
magnetite mixture, where the feed is entirely magnetite,
the average size further decreases to 39.49 µm in zone 1.
Figure 5. Comparison of mean particle size distributions of a) magnetite and b) silica of pure feed in separation zones
Figure 6. Comparison of mean particle size distributions of magnetite and silica in feed proportions of a) 20: 80 b) 50:50 in
separation zones