4
considered normal variation. This conclusion is validated
further with statistical analysis in the following section.
ANOVA test
An ANOVA test was carried out to interpret the statistical
effects of each factor on the response, i.e., copper extraction
in reactors. The factors tested were catalyst (A), initial iron
concentration (B), and lixiviant
(C). Factor C was included as a categorical factor
with input -1 (inoculum,) or +1 (synthetic raffinate). The
ANOVA test results are summarized in Table 6.
Catalyst (A), lixiviant (C), and the interaction between
these two factors (AC) all have a statistically significant
effect (p 0.05) on the copper extraction. Based on this
model, iron does not contribute to copper extraction,
which further validates the observations made in the previ-
ous section.
The F-values indicate that the presence of catalyst had
the largest impact on copper extraction. This is followed
next by lixiviant and the interaction of the two factors.
Normalizing the coefficients in the model shows that the
presence of catalyst accounts for 25% increase in response
of the model. While synthetic raffinate contributes to a 9%
decrease in response compared to inoculum. Finally, there
is a minimal effect on the response (6%) from the com-
bined interaction between the lixiviant and catalyst.
CONCLUSION
Jetti’s catalytic technology works synergistically with
biooxidation to leach chalcopyrite which would otherwise
be unleachable. Under optimal conditions, the Jetti catalyst
can provide a copper extraction 2.6x higher in bioreactors
compared to tests under non catalyzed conditions. In reac-
tor tests using sub-optimal commercial raffinate, the pres-
ence of catalyst increased copper extraction by 1.9 times
compared to the control.
REFERENCES
[1] Schlesinger, M.E., King, M.J., Sole, K.C. and
Davenport, W.G. (2011), Extractive metallurgy of cop-
per, 5th edn., Amsterdam Boston, Elsevier.
[2] 2022, “The world copper factbook,” International
Copper Study Group (ICSG).
[3] Ren, Z., Chao, C., Krishnamoorthy, P., Asselin, E.,
Dixon, D.G. and Mora, N. (2022), “The overlooked
mechanism of chalcopyrite passivation,” Acta mate-
rialia, vol. 236, pp. 118111.
Table 6. ANOVA test summary
Source
Sum of
Squares df
Mean
Square
F-
Value
p-
Value
Model 2406.07 4 601.52 2970.46 0.0138
A-Catalyst 2020.21 1 2020.21 9976.33 0.0064
B-Fe 23.52 1 23.52 116.16 0.0589
C-Lixiviant 189.06 1 189.06 933.64 0.0208
AC 132.67 1 132.67 655.15 0.0249
Error 0.2025 1 0.2025
Total 2406.27 5
considered normal variation. This conclusion is validated
further with statistical analysis in the following section.
ANOVA test
An ANOVA test was carried out to interpret the statistical
effects of each factor on the response, i.e., copper extraction
in reactors. The factors tested were catalyst (A), initial iron
concentration (B), and lixiviant
(C). Factor C was included as a categorical factor
with input -1 (inoculum,) or +1 (synthetic raffinate). The
ANOVA test results are summarized in Table 6.
Catalyst (A), lixiviant (C), and the interaction between
these two factors (AC) all have a statistically significant
effect (p 0.05) on the copper extraction. Based on this
model, iron does not contribute to copper extraction,
which further validates the observations made in the previ-
ous section.
The F-values indicate that the presence of catalyst had
the largest impact on copper extraction. This is followed
next by lixiviant and the interaction of the two factors.
Normalizing the coefficients in the model shows that the
presence of catalyst accounts for 25% increase in response
of the model. While synthetic raffinate contributes to a 9%
decrease in response compared to inoculum. Finally, there
is a minimal effect on the response (6%) from the com-
bined interaction between the lixiviant and catalyst.
CONCLUSION
Jetti’s catalytic technology works synergistically with
biooxidation to leach chalcopyrite which would otherwise
be unleachable. Under optimal conditions, the Jetti catalyst
can provide a copper extraction 2.6x higher in bioreactors
compared to tests under non catalyzed conditions. In reac-
tor tests using sub-optimal commercial raffinate, the pres-
ence of catalyst increased copper extraction by 1.9 times
compared to the control.
REFERENCES
[1] Schlesinger, M.E., King, M.J., Sole, K.C. and
Davenport, W.G. (2011), Extractive metallurgy of cop-
per, 5th edn., Amsterdam Boston, Elsevier.
[2] 2022, “The world copper factbook,” International
Copper Study Group (ICSG).
[3] Ren, Z., Chao, C., Krishnamoorthy, P., Asselin, E.,
Dixon, D.G. and Mora, N. (2022), “The overlooked
mechanism of chalcopyrite passivation,” Acta mate-
rialia, vol. 236, pp. 118111.
Table 6. ANOVA test summary
Source
Sum of
Squares df
Mean
Square
F-
Value
p-
Value
Model 2406.07 4 601.52 2970.46 0.0138
A-Catalyst 2020.21 1 2020.21 9976.33 0.0064
B-Fe 23.52 1 23.52 116.16 0.0589
C-Lixiviant 189.06 1 189.06 933.64 0.0208
AC 132.67 1 132.67 655.15 0.0249
Error 0.2025 1 0.2025
Total 2406.27 5