4
**
***
***
*.7^central
Rec Au pH PAX
AR1404 pH PAX
pH AR1404 PAX
AR1404
25.2 6.05 2145 660
245 98
2113
4 pointh
=+++
--
+
+
^%h
(1)
whose correlation coefficient (R2) is 0.9148, indicat-
ing that all the collected data is valid. Finally, optimizing
Equation 1, the optimal values to use would be a dosage of
PAX: 0.03, AR1404: 0.05 kg/t, and a pH of 6.5 to achieve
a Gold Recovery of 86.66%
Analysis of the Environmental Impact and Subsequent
Use of Tailings
Analyzing the assays of the initial sample and the final tail-
ings obtained from the flotation tests carried out, the fol-
lowing can be observed. The initial sample, concerning its
sulfide mineralogical composition, consists of 9.79% sul-
fides, with 5.69% being pyrite, 2.14% arsenopyrite, and
0.24% galena. In terms of alkaline mineralogical compo-
sition, it contains 4.11% alkaline minerals, with 3.63%
being calcite and 0.48% dolomite. On the other hand,
the final tailings sample regarding the sulfide mineralogi-
cal composition, has 0.27% of sulfides where the total is
pyrite. Regarding the alkaline mineralogical composition, it
has 4.44% in alkaline minerals, where 3.73% is calcite and
0.71% is dolomite.
In order to know whether the sample will generate
acid mine drainage (AMD), it is crucial to determine the
net neutralization potential (NNP) of the sample. NNP is
calculated based on the content of sulfide minerals, which
quantifies the acid potential (AP), contrasted with the net
content of acid-consuming or alkaline minerals (NP). NNP
is defined by the following Equation 2.
NNP NP AP – =(2)
where
AP= %S*31.25 kg CaCO3/1,000 kg
NP= kg CaCO3/1,000 kg
Considering the following criteria:
• If NNP +20 kg CaCO3/1000 kg of material, no
acid drainage will occur, or if NP/AP 3.
• If NNP 0 and NP/AP 1, in this case, acid drain-
age will occur.
According to these criteria and using the data from the
assays of the initial and the final tailings samples, the results
are presented in Table 8.
According to these results, the conclusion is that the
initial sample of tailings from the Marañon processing
plant will indeed produce acid mine drainage, generating
a risk of arsenic discharge in the liquid effluents of these
tailings. Regarding the final tailings from the flotation tests
after the flotation of all sulfides, it will not produce acid
mine drainage and, consequently, will not release arsenic
into the solution due to having an NNP greater than 20.
Another advantage of this method is the potential to
reduce the volume of disposed tailings by manufactur-
ing bricks for the construction industry near the Poderosa
mine. Additionally, ornamental products can be manufac-
tured using only cement and sodium silicate at ambient
temperatures. In Figures 3 and 4, both bricks and orna-
mental products can be seen.
CONCLUSIONS AND RECOMMENDATIONS
Characterization of Marañon tailings revealed that gold
was found in high concentrations in arsenopyrite. Once the
particle size distribution indicated that 90% of gold and
silver were located in particles below 74 μm. This indicated
Table 8. Tailings net neutralization potential (NNP)
Sample
Assays, %
Potential (t
CaCO
3 /1000kg) Ratio
CaCO3 S–2 AP NP NNP NP/AP
Initial
sample
3.89 4.03 125.9 38.9 –87.04 0.3
Final
tailings
4.12 0.14 4.4 41.2 36.83 9.4
Figure 3. Manufactured bricks using final tailings from flotation tests
**
***
***
*.7^central
Rec Au pH PAX
AR1404 pH PAX
pH AR1404 PAX
AR1404
25.2 6.05 2145 660
245 98
2113
4 pointh
=+++
--
+
+
^%h
(1)
whose correlation coefficient (R2) is 0.9148, indicat-
ing that all the collected data is valid. Finally, optimizing
Equation 1, the optimal values to use would be a dosage of
PAX: 0.03, AR1404: 0.05 kg/t, and a pH of 6.5 to achieve
a Gold Recovery of 86.66%
Analysis of the Environmental Impact and Subsequent
Use of Tailings
Analyzing the assays of the initial sample and the final tail-
ings obtained from the flotation tests carried out, the fol-
lowing can be observed. The initial sample, concerning its
sulfide mineralogical composition, consists of 9.79% sul-
fides, with 5.69% being pyrite, 2.14% arsenopyrite, and
0.24% galena. In terms of alkaline mineralogical compo-
sition, it contains 4.11% alkaline minerals, with 3.63%
being calcite and 0.48% dolomite. On the other hand,
the final tailings sample regarding the sulfide mineralogi-
cal composition, has 0.27% of sulfides where the total is
pyrite. Regarding the alkaline mineralogical composition, it
has 4.44% in alkaline minerals, where 3.73% is calcite and
0.71% is dolomite.
In order to know whether the sample will generate
acid mine drainage (AMD), it is crucial to determine the
net neutralization potential (NNP) of the sample. NNP is
calculated based on the content of sulfide minerals, which
quantifies the acid potential (AP), contrasted with the net
content of acid-consuming or alkaline minerals (NP). NNP
is defined by the following Equation 2.
NNP NP AP – =(2)
where
AP= %S*31.25 kg CaCO3/1,000 kg
NP= kg CaCO3/1,000 kg
Considering the following criteria:
• If NNP +20 kg CaCO3/1000 kg of material, no
acid drainage will occur, or if NP/AP 3.
• If NNP 0 and NP/AP 1, in this case, acid drain-
age will occur.
According to these criteria and using the data from the
assays of the initial and the final tailings samples, the results
are presented in Table 8.
According to these results, the conclusion is that the
initial sample of tailings from the Marañon processing
plant will indeed produce acid mine drainage, generating
a risk of arsenic discharge in the liquid effluents of these
tailings. Regarding the final tailings from the flotation tests
after the flotation of all sulfides, it will not produce acid
mine drainage and, consequently, will not release arsenic
into the solution due to having an NNP greater than 20.
Another advantage of this method is the potential to
reduce the volume of disposed tailings by manufactur-
ing bricks for the construction industry near the Poderosa
mine. Additionally, ornamental products can be manufac-
tured using only cement and sodium silicate at ambient
temperatures. In Figures 3 and 4, both bricks and orna-
mental products can be seen.
CONCLUSIONS AND RECOMMENDATIONS
Characterization of Marañon tailings revealed that gold
was found in high concentrations in arsenopyrite. Once the
particle size distribution indicated that 90% of gold and
silver were located in particles below 74 μm. This indicated
Table 8. Tailings net neutralization potential (NNP)
Sample
Assays, %
Potential (t
CaCO
3 /1000kg) Ratio
CaCO3 S–2 AP NP NNP NP/AP
Initial
sample
3.89 4.03 125.9 38.9 –87.04 0.3
Final
tailings
4.12 0.14 4.4 41.2 36.83 9.4
Figure 3. Manufactured bricks using final tailings from flotation tests