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X JORNADA DE INVESTIGACIÓN EN
CIENCIAS EXPERIMENTALES Y DE LA
SALUD
UNIVERSIDAD DE NAVARRA
Libro de resúmenes
PAMPLONA, 6 DE ABRIL DE 2017
X Jornada de Investigación en Ciencias Experimentales y de la Salud de la Universidad de Navarra
71
FÍSICA, QUÍMICA y
MATEMÁTICAS
X Jornada de Investigación en Ciencias Experimentales y de la Salud de la Universidad de Navarra
76
Póster nº 57
Física, Química y Matemáticas
SOLIDIFICATION/STABILIZATION OF HAZARDOUS WASTES FROM THE MINE “LA PRIETA” IN HIDALGO DEL PARRAL, CHIHUAHUA, MEXICO
Jesús Fidel González Sánchez, José María Fernández Álvarez,
José Ignacio Álvarez Galindo, Íñigo Navarro-Blasco
Departamento de Química, Universidad de Navarra
e-mail: [email protected]
The mining industry of Mexico is one of the oldest and most useful activity for the Mexican economy,
however it has a high environment impact from the subsoil to the atmosphere. It generates a large amount of
solid, liquid and gaseous wastes. The most impacted mining wastes are tailings due to the high content of
toxic components.
One of the most widespread alternatives for handling toxic metal is the blocking in a manageable solid
system which allows the proper solidification/stabilization (S/S) of hazardous components and its subsequent
safe disposal.
Ordinary Portland Cement (OPC) has been widely studied to retain potentially toxic heavy metals, but the
use of other alternative binders is receiving growing attention. For instance, the use of Calcium Aluminate
Cement (CAC) to safely encapsulate hazardous materials has proved to be highly effective.
In this study both binding matrices, OPC and CAC, were assayed to encapsulate loaded naturally toxic metal
mining tailings with the aim to obtain a waste-containing solid block with improved management and
successfully disposal. A semi-dynamic Tank Test (EA NEN 7375, 2004) was applied in elucidating leaching
mechanisms and to evaluate the supporting evidence in solidify/stabilize of these hazardous wastes in this
type of cement-based matrices.
Dónde:
Stabilization/solidification of hazardous wastes from the mine “La Prieta” in Hidalgo del Parral, Chihuahua, Mexico
González Sánchez, Jesús Fidel; Fernández Álvarez, José María; Álvarez Galindo, José Ignacio; Navarro-Blasco, IñigoInorganic materials and environment research Group (MIMED). Department of Chemistry
INTRODUCTIONThe mining industry of Mexico is one of the oldest and most useful activity for the Mexican economy [1]. However, it has a high environment impact from the subsoil
to the atmosphere. It generates a large amount of solid, liquid and gaseous wastes. Due to the high content of toxic components, tailings are the most impacted
mining wastes[2]. The blocking in a manageable solid system is the most widespread alternative for handling toxic metal. It allows the proper
solidification/stabilization (s/s) of hazardous components and its subsequent safe disposal.
Ordinary portland cement (OPC) has been widely studied to retain potentially toxic heavy metals, but the use of other alternative binders is receiving growing
attention. For instance, the use of calcium aluminate cement (CAC) to safely encapsulate hazardous materials has proved to be highly effective [3].
OBJECTIVEThe binding matrices, OPC, calcium aluminate cement white (CACw) and calcium
aluminate cement dark (CACd) to encapsulate loaded naturally toxic metal mining
tailings with the aim to obtain a waste-containing solid block with improvedmanagement and successfully disposal, were assayed.
AREA OF STUDY AND SAMPLINGThe sampling was carried out at the mine "La Prieta" Hidalgo del Chihuahua, Mexico,
in according with the specifications described by official norm NMX-AA-132-SCFI-2006.
LEACHING TESTThe cylindrical specimens were subjected to the tank test according to EA NEN 7375
standard, which consists of placing in methacrylate containers and filled with 1 liter of
neutral pH demineralized water in order to obtain the leachate, over a period of 64
days, as shown in figures:
In addition, the characteristics of the monolithic structures were studied, obtaining
the following resistance to compression and porosity profiles:
SOLUTIONIn order to treat the toxic elements, the Stabilization /Solidification in cement
matrices was used, for which the following materials were used:
CUANTIFICATION OF THE TOXIC ELEMENTSThe collected samples were subjected to acid digestion to analyze potentially toxic
elements following the methodology of the EPA-3050b standard. The elements
quantified by the atomic absorption spectrophotometry method were As, Pb and Zn,
where the following levels were found:
A sample of the leachate was collected and drained off at eight different times (0.25,
1, 2.25, 4, 9, 16, 36 and 64 days) then it was analyzed using atomic absorption
spectrophotometry to quantify the amount of pollutant in the leachate , obtaining the
following retaining results:
CONCLUSION
1. The stabilization/solidification treatment is adequate to treat mining tailings, due to
more than 98% of the contaminants are encapsulated in addition that the Pb, As and
Zn concentrations are high in the study area.
2. A thorough selection of the binder material should be carried out. As it happened
with this kind of tailing samples, the high sulphate content has brought to the form of
an expansive compound, ettringite, by reaction with the high alumina content in CAC
mortars, which make the monolithic unable to encapsulate the mining waste.
3. OPC mortar is a more appropriate system to encapsulate load naturally toxic metal
mining tailings from the mine “La Prieta” in Hidalgo del Parral, Mexico.
0100020003000400050006000700080009000
100001100012000
HP2 HP3 HP5 HP7 HP16 HP17
Co
nce
ntr
atio
n (
mg
/kgs
oil)
Samples
Zn Pb As
OPC CACw CACdMIX 1 MIX 2 MIX 1 MIX 2 MIX 1 MIX 2
Substitution
aggregate50 % 15% 50 % 15 % 50 % 15 %
Cement 34 34 32 32 35 35
Siliciuos Agregate 29 50 31 52 29 49
Mine Waste 29 9 31 9 29 9
HMP 7 7 6 6 7 7
Water 13 13 12 12 12 12
CharacteristicsReleases heat
in the reaction-
Expansion
of the test
piece
Expansion
of the test
piece
Releases heat
in the reaction and
expansion
of the test piece
Releases heat
in the reaction and
expansion
of the test piece
(only test piece HP3)
0
20
40
60
80
100
HP2 HP3 HP5 HP7 HP16 HP17
LOA
D (
MPA
)
SAMPLE
Compresive strength
OPC 50%
OPC 15%
CACd 15%
90.0
91.0
92.0
93.0
94.0
95.0
96.0
97.0
98.0
99.0
100.0
HP2 HP3 HP5 HP7 HP16 HP17
RET
AIN
ED %
SAMPLE
Retained Zn
OPC 50%
OPC 15%
CACd 15%
90.0
91.0
92.0
93.0
94.0
95.0
96.0
97.0
98.0
99.0
100.0
HP2 HP3 HP5 HP7 HP16 HP17
RET
AIN
ED%
SAMPLE
Retained Pb
OPC 15%
OPC 50%
CACd 15%
90.0
91.0
92.0
93.0
94.0
95.0
96.0
97.0
98.0
99.0
100.0
HP2 HP3 HP5 HP7 HP16 HP17
RET
AIN
ED %
SAMPLE
Retained As
OPC 50%
OPC 15%
CACd 15%
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0.20
0.001 0.01 0.1 1 10 100 1000
Log
Dif
fere
nti
al
Intr
usi
on
(m
L g
-1)
Pore Size Diameter (µm)
OPC 50%
HP2
HP3
HP5
HP7
HP16
HP17
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0.20
0.001 0.01 0.1 1 10 100 1000
Log
Dif
fere
nti
al
Intr
usi
on
(m
L g
-1)
Pore Size Diameter (µm)
OPC 15%HP2
HP3
HP5
HP7
HP16
HP17
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.001 0.01 0.1 1 10 100 1000
Log
Dif
fere
nti
al
Intr
usi
on
(mL
g-1
)
Pore Size Diameter (µm)
CACd 15 %
HP2
HP5
HP7
HP16
HP17
Porosimetry
References[1]Cortinas, C. 2007. Instituto Nacional de Ecología. Instituto Nacional de Ecología. http://www2.inecc.gob.mx/publicaciones/gacetas/155/cortinas.html.
[2]Griffin, R. D. 2009. Principles of Hazardous Materials Management. Michigan : CRC Press, 2009.
[3]Lasheras-Zubiate M., Navarro-Blasco I., Fernández J.M., Álvarez J.I., 2012 Encapsulation, solid-phase identification and leaching of toxic metals in cement systems modified
by natural biodegradable polymers, J. Hazard. Mater. 233–234 (2012) 7–17.[4]EA NEN 7375, Leaching characteristics of moulded or monolithic building and waste materials, Determination of leaching of inorganic components with the diffusion test, 2004.
OPC 15%
OPC 50%
CACw 15% & 50%
CACd 15%
CACd 50%