3104 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
CONCLUSIONS
Hostaflot-7650 with a dosage PAX/promoter of 280/100 g/t
can be recommended against the currently used combina-
tion PAX/AERO238 at the Krumovgrad operation. The
main supporting argument is that improved performance
was obtained during a comparative testing campaign with
this combination achieving 85.3% gold recovery, good
reproducibility and with a reduced dosage of PAX.
The DP-OMC from BASF secured lower gold recov-
ery than the Hostaflot series. However, the low correlation
between mass pull and Au recovery suggests that most of
the material is recovered thanks to true flotation and not
mechanical entrainment.
Hostaflot-10093 gave the highest Au recovery from all
tests (86.4%), but results are characterized by lower repro-
ducibility as promoter dosage increases.
Hostaflot-LIB witnessed higher reproducibility com-
pared to Hostaflot-7650 and Hostaflot-10093 and achieved
comparably high recovery (84.9%). However at reduced
PAX dosage, recovery dropped to 84.1%.
The Au/Ag ratio in electrum grains could be used as a
metric for particles floatability, with the higher ratio of sil-
ver resulting in increased precious metals losses to tailings.
The SEM-EDS observations of grains detected in the
streams suggest relatively good flotation response of the ore
for the studied collector/promoter combinations. The rea-
sons for Au losses in tailings are general the result of insuf-
ficient electrum liberation inside fine particle size classes.
The tailings samples are challenging when it comes to
SEM-EDS detection of a statistically reliable number of
electrum grains, therefore preconcentration through grav-
ity separation is recommended for future analysis in order
to increase the number of particles observed.
ACKNOWLEDGMENT
The authors are grateful to DPM-Krumovgrad for sup-
porting the work and for permission to communicate the
results. The reagents suppliers are gratefully acknowledged
for furnishing samples from their commercial portfolio for
testing.
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