2562 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
to the assumed optimal parameter settings obtained during
batch flotation where pH in the rougher stage converges to
the interval [9.5,10], pH in the cleaner stage to the interval
[9,10], the collector dosage to the interval [70,100] g/t and
the frother dosage to the interval [20,45] g/t.
As for the parameters Quebracho dosage and colloidal
silica dosage which were kept free to vary in the simpli-
fied simplex, the 2D density plots in Figure 8 show that
the parameters converge almost to the same area in the full
and simplified simplex with the convergence interval being
[20,25] g/t for Quebracho dosage and [250,350] g/t for
colloidal silica dosage.
Table 9 illustrates the best performance results so far
for the full and the simplified simplex after 4 iterations. The
results show that on the one hand there is an improvement
in scheelite-calcite selectivity when colloidal silica is imple-
mented in the reagent system compared to the benchmark
process, on the other hand almost the same results are
obtained with the full and the simplified simplex. The dif-
ference is that 60% fewer experiments are performed with
the simplified simplex and proportionally less material,
energy and time are consumed.
Industrial Scale
After successfully testing the reagents on a pilot scale,
a three-day industry campaign was carried out using the
Nelder-Mead optimization algorithm. To evaluate the
results, a GRP index (Grade Recovery Performance Index)
was developed to evaluate the process results in two dimen-
sions (scheelite grade and recovery). In consultation with
the mining company, the process parameters Quebracho
dosage, collector dosage and colloidal silica dosage were
varied. The frother dosage was kept constant due to its
insignificant effect on the batch scale. As the pH value was
Figure 7. Convergence zone of the full simplex for the process parameter a) pH and b) collector and frother dosages in
rougher and cleaner stages after 4 iterations
Figure 8. Convergence zone of the process parameters Quebracho dosage and colloidal silica dosage for the a) full and b)
simplified simplex after 4 iterations
to the assumed optimal parameter settings obtained during
batch flotation where pH in the rougher stage converges to
the interval [9.5,10], pH in the cleaner stage to the interval
[9,10], the collector dosage to the interval [70,100] g/t and
the frother dosage to the interval [20,45] g/t.
As for the parameters Quebracho dosage and colloidal
silica dosage which were kept free to vary in the simpli-
fied simplex, the 2D density plots in Figure 8 show that
the parameters converge almost to the same area in the full
and simplified simplex with the convergence interval being
[20,25] g/t for Quebracho dosage and [250,350] g/t for
colloidal silica dosage.
Table 9 illustrates the best performance results so far
for the full and the simplified simplex after 4 iterations. The
results show that on the one hand there is an improvement
in scheelite-calcite selectivity when colloidal silica is imple-
mented in the reagent system compared to the benchmark
process, on the other hand almost the same results are
obtained with the full and the simplified simplex. The dif-
ference is that 60% fewer experiments are performed with
the simplified simplex and proportionally less material,
energy and time are consumed.
Industrial Scale
After successfully testing the reagents on a pilot scale,
a three-day industry campaign was carried out using the
Nelder-Mead optimization algorithm. To evaluate the
results, a GRP index (Grade Recovery Performance Index)
was developed to evaluate the process results in two dimen-
sions (scheelite grade and recovery). In consultation with
the mining company, the process parameters Quebracho
dosage, collector dosage and colloidal silica dosage were
varied. The frother dosage was kept constant due to its
insignificant effect on the batch scale. As the pH value was
Figure 7. Convergence zone of the full simplex for the process parameter a) pH and b) collector and frother dosages in
rougher and cleaner stages after 4 iterations
Figure 8. Convergence zone of the process parameters Quebracho dosage and colloidal silica dosage for the a) full and b)
simplified simplex after 4 iterations