2
• Recover valuable resources from tailings of Poderosa’s
processing plant named Marañon,
• Minimize environmental impact,
• Generate products to market.
CHARACTERIZATION
The mineralogy and its composition were determined via
X-ray diffraction (XRD) analysis conducted in the Cia.
Minera Poderosa laboratory. The results are presented in
Figure 1 and Table 1.
The mineral bonds in the Marañon tailings were ana-
lyzed through Scanning Electron Microscopy (SEM) at the
FA INGENIEROS SAC laboratories. The results can be
found in Table 2.
Using Energy-Dispersive Spectrometry (EDS) in
the SEM, the presence of gold was identified within
arsenopyrite. Based on previous experience, it is known that
arsenopyrite exhibits refractory behavior to cyanidation.
The results of the gold and silver assays, conducted
at the Cia Minera Poderosa laboratory, are presented in
Table 3.
The gold and silver values in particles were examined
through particle size distribution assays. It was observed
that 46.4% of the sample’s mass was below 37 μm, and
90% of the gold and silver were found in particles smaller
than 74 μm.
FLOTATION TESTS
Based on the Marañon tailings characterization, it was
determined that regrinding this material was unnecessary. A
series of preliminary flotation tests were conducted, where
variations were made in the addition of collectors such as
potassium amyl xanthate (PAX), sodium dithiophosphate
(AR1404), and sodium isopropyl xanthate. These tests
demonstrated the effectiveness of flotation for the recovery
of gold and silver from the tailings, and a batch flotation
testing scheme could be performed in open circuits using
rougher, scavenger, and cleaner stages.
In the context of a closed-circuit mass balance, distri-
bution coefficients were used, accounting for the recircula-
tion of cleaner tailings and scavenger concentrate into the
feed. The parameters and results are presented in Table 4
and Table 5.
Design of Experiments
An experimental design was performed with the tailings
sample, to study the effect of the pH and the dosages of
Figure 1. X-ray diffractogram, flotation tailings of Marañon
processing plant. 40Kv/40 mA Cu-Ni
Table 1. Phases and composition of tailings from the
Marañon processing plant
Mineral Phases
Composition
(%)
Quartz SiO2 52.07
Clinochlore (Mg,Fe)
5 Al(Si
3 Al)O
10 (OH)
8 11.79
Albite AlNaO
8 Si
3 9.42
Illite Al2HKO12Si4 9.20
Pyrite FeS2 5.69
Calcite CaCO
3 3.63
Muscovite K(Al
2 Fe
12 )(Si
3 Al)O
10 (OH)
2 2.93
Arsenopyrite AsFeS 2.14
Sphalerite (Zn,Fe)S 1.72
Galena PbS 0.24
Dolomite CaMg(CO
3 )
2 0.48
Ortoclase AlKO8Si3 0.04
Actinolite Ca2(Mg,Fe)5Si8O22(OH)2 0.64
Total 99.99
Table 2. SEM results of the Marañon tailings sample
Mineral Description
Size
(μm)
Gypsum Fibrous form. Found intergrown with
galena and pyrite.
25
Arsenopyrite Subhedral forms with rhombic
habits. Found as free particles and
intergrown with galena.
2-40
Galena Irregular and subrounded forms. It is
intergrown with arsenopyrite.
20
Sphalerite Irregular sizes. Found as free particles 30
Pyrite Irregular forms. It is intergrown with
galena.
20
Table 3. Marañón Tailings Assays
Sample
Au,
g/t
Ag,
g/t
Pb,
%
Zn,
%
As,
%
Fe,
%
S,
%
Tailings 1.6 13.6 0.21 1.15 0.99 3.39 4.06
• Recover valuable resources from tailings of Poderosa’s
processing plant named Marañon,
• Minimize environmental impact,
• Generate products to market.
CHARACTERIZATION
The mineralogy and its composition were determined via
X-ray diffraction (XRD) analysis conducted in the Cia.
Minera Poderosa laboratory. The results are presented in
Figure 1 and Table 1.
The mineral bonds in the Marañon tailings were ana-
lyzed through Scanning Electron Microscopy (SEM) at the
FA INGENIEROS SAC laboratories. The results can be
found in Table 2.
Using Energy-Dispersive Spectrometry (EDS) in
the SEM, the presence of gold was identified within
arsenopyrite. Based on previous experience, it is known that
arsenopyrite exhibits refractory behavior to cyanidation.
The results of the gold and silver assays, conducted
at the Cia Minera Poderosa laboratory, are presented in
Table 3.
The gold and silver values in particles were examined
through particle size distribution assays. It was observed
that 46.4% of the sample’s mass was below 37 μm, and
90% of the gold and silver were found in particles smaller
than 74 μm.
FLOTATION TESTS
Based on the Marañon tailings characterization, it was
determined that regrinding this material was unnecessary. A
series of preliminary flotation tests were conducted, where
variations were made in the addition of collectors such as
potassium amyl xanthate (PAX), sodium dithiophosphate
(AR1404), and sodium isopropyl xanthate. These tests
demonstrated the effectiveness of flotation for the recovery
of gold and silver from the tailings, and a batch flotation
testing scheme could be performed in open circuits using
rougher, scavenger, and cleaner stages.
In the context of a closed-circuit mass balance, distri-
bution coefficients were used, accounting for the recircula-
tion of cleaner tailings and scavenger concentrate into the
feed. The parameters and results are presented in Table 4
and Table 5.
Design of Experiments
An experimental design was performed with the tailings
sample, to study the effect of the pH and the dosages of
Figure 1. X-ray diffractogram, flotation tailings of Marañon
processing plant. 40Kv/40 mA Cu-Ni
Table 1. Phases and composition of tailings from the
Marañon processing plant
Mineral Phases
Composition
(%)
Quartz SiO2 52.07
Clinochlore (Mg,Fe)
5 Al(Si
3 Al)O
10 (OH)
8 11.79
Albite AlNaO
8 Si
3 9.42
Illite Al2HKO12Si4 9.20
Pyrite FeS2 5.69
Calcite CaCO
3 3.63
Muscovite K(Al
2 Fe
12 )(Si
3 Al)O
10 (OH)
2 2.93
Arsenopyrite AsFeS 2.14
Sphalerite (Zn,Fe)S 1.72
Galena PbS 0.24
Dolomite CaMg(CO
3 )
2 0.48
Ortoclase AlKO8Si3 0.04
Actinolite Ca2(Mg,Fe)5Si8O22(OH)2 0.64
Total 99.99
Table 2. SEM results of the Marañon tailings sample
Mineral Description
Size
(μm)
Gypsum Fibrous form. Found intergrown with
galena and pyrite.
25
Arsenopyrite Subhedral forms with rhombic
habits. Found as free particles and
intergrown with galena.
2-40
Galena Irregular and subrounded forms. It is
intergrown with arsenopyrite.
20
Sphalerite Irregular sizes. Found as free particles 30
Pyrite Irregular forms. It is intergrown with
galena.
20
Table 3. Marañón Tailings Assays
Sample
Au,
g/t
Ag,
g/t
Pb,
%
Zn,
%
As,
%
Fe,
%
S,
%
Tailings 1.6 13.6 0.21 1.15 0.99 3.39 4.06