1
24-046
Geopolymerization of Mining Tailings as an Alternative for
Its Use in the Construction Industry
C. Toledo
Pontifical Catholic University of Peru, Lima, Peru
M. Guzman
Pontifical Catholic University of Peru, Lima, Peru
J. A. Rau
Pontifical Catholic University of Peru, Lima, Peru
Patrizia Pereyra
Pontifical Catholic University of Peru, Lima, Peru
A. Ruiz
Instituto Peruano de Prospectores y Desarrolladores,
Lima, Peru
ABSTRACT
The use of mining tailings-based geopolymer binder as a
substitute for cement can be an interesting alternative to
the problem of final disposing of large volumes of them.
Indeed, mining tailings have a high silica content, which
makes them suitable for geopolymerization. The tailings
samples contain Cu, Pb, Zn, As, Sb, Cd and Bi, mainly.
X-ray diffraction results show that the tailings are com-
posed of quartz, SiO2 (81%). Geopolymerized tailing sam-
ples (GTPS) were obtained by varying the ratio of SiO2/
Al2O3 and SiO2/NaOH. The compressive strength of the
GTPS varied between 2 MPa and 8 MPa. The electrical
conductivity in the leaching tests varies between 13.91–
16.11 mS/cm2 indicating that ions are present in the solu-
tion. However, the pH =10.5 indicates that acidity is not
being generated. The element that mostly leaches is iron.
The highest percentage of leaching is observed for cadmium
(69%) and chromium (93%). The concentrations of ele-
ments are under the maximum permissible limits for water
according to the Peruvian legislation. However, mass trans-
fer leach tests and immersion leach tests must be realized.
INTRODUCTION
Mining is an important industry in the economy of many
countries. For mining operations to develop, the movement
of large volumes of material is necessary. In this sense, this
industry generates a variety of solid and semi-solid waste,
with tailings being one of the largest volume products gen-
erated [1]. In fact, the mining industry generates a huge
amount of mine tailings from the excavation of minerals in
the form of waste rock from mineral processing [2]. In this
sense, it is necessary to implement an adequate manage-
ment system for the waste generated [3,4].
In recent years, the mining industry around the world
has focused its efforts on minimizing this waste, either by
reusing it in its operations with the cut-and-fill method
[5,6] or looking for alternative uses in society [7]. Another
problem with tailings is related to the handling of large
volumes that must be disposed of safely [8–10]. One way
to reduce or minimize the volume of this waste is to use
it as raw material for the production of inputs for other
industries [11], such as construction [10, 12–16]. The lit-
erature has shown that it is possible to use copper tailings
[2,17,18], gold [18–22] and iron [23–30] mixed with geo-
polymers [18,23,25] as partial Cement substitute for con-
crete or making construction bricks. In this sense, the use
of geopolymerized mine tailings is a new trend of great rel-
evance in the mining industry and especially useful for the
reuse of tailings [31–33, 34]. In this article, the preliminary
results of obtaining geopolymerized cement from mine tail-
ings are presented.
24-046
Geopolymerization of Mining Tailings as an Alternative for
Its Use in the Construction Industry
C. Toledo
Pontifical Catholic University of Peru, Lima, Peru
M. Guzman
Pontifical Catholic University of Peru, Lima, Peru
J. A. Rau
Pontifical Catholic University of Peru, Lima, Peru
Patrizia Pereyra
Pontifical Catholic University of Peru, Lima, Peru
A. Ruiz
Instituto Peruano de Prospectores y Desarrolladores,
Lima, Peru
ABSTRACT
The use of mining tailings-based geopolymer binder as a
substitute for cement can be an interesting alternative to
the problem of final disposing of large volumes of them.
Indeed, mining tailings have a high silica content, which
makes them suitable for geopolymerization. The tailings
samples contain Cu, Pb, Zn, As, Sb, Cd and Bi, mainly.
X-ray diffraction results show that the tailings are com-
posed of quartz, SiO2 (81%). Geopolymerized tailing sam-
ples (GTPS) were obtained by varying the ratio of SiO2/
Al2O3 and SiO2/NaOH. The compressive strength of the
GTPS varied between 2 MPa and 8 MPa. The electrical
conductivity in the leaching tests varies between 13.91–
16.11 mS/cm2 indicating that ions are present in the solu-
tion. However, the pH =10.5 indicates that acidity is not
being generated. The element that mostly leaches is iron.
The highest percentage of leaching is observed for cadmium
(69%) and chromium (93%). The concentrations of ele-
ments are under the maximum permissible limits for water
according to the Peruvian legislation. However, mass trans-
fer leach tests and immersion leach tests must be realized.
INTRODUCTION
Mining is an important industry in the economy of many
countries. For mining operations to develop, the movement
of large volumes of material is necessary. In this sense, this
industry generates a variety of solid and semi-solid waste,
with tailings being one of the largest volume products gen-
erated [1]. In fact, the mining industry generates a huge
amount of mine tailings from the excavation of minerals in
the form of waste rock from mineral processing [2]. In this
sense, it is necessary to implement an adequate manage-
ment system for the waste generated [3,4].
In recent years, the mining industry around the world
has focused its efforts on minimizing this waste, either by
reusing it in its operations with the cut-and-fill method
[5,6] or looking for alternative uses in society [7]. Another
problem with tailings is related to the handling of large
volumes that must be disposed of safely [8–10]. One way
to reduce or minimize the volume of this waste is to use
it as raw material for the production of inputs for other
industries [11], such as construction [10, 12–16]. The lit-
erature has shown that it is possible to use copper tailings
[2,17,18], gold [18–22] and iron [23–30] mixed with geo-
polymers [18,23,25] as partial Cement substitute for con-
crete or making construction bricks. In this sense, the use
of geopolymerized mine tailings is a new trend of great rel-
evance in the mining industry and especially useful for the
reuse of tailings [31–33, 34]. In this article, the preliminary
results of obtaining geopolymerized cement from mine tail-
ings are presented.