INGEOSUR   20376
INSTITUTO GEOLOGICO DEL SUR
Unidad Ejecutora - UE
artículos
Título:
Environmental suitability of ceramic raw materials: a geochemical approach to volatile emissions and leaching potentials.
Autor/es:
E. DOMINGUEZ; MICHELE DONDI; IGLESIAS CLAUDIO
Revista:
Environmental Earth Sciences
Editorial:
Springer
Referencias:
Año: 2011 vol. 65 p. 517 - 523
ISSN:
1866-6280
Resumen:
Growing environmental concern is promoting
the necessity of additional ceramic tests. The use of
unknown materials with potential contamination conditions
requires further studies to demonstrate that the piece
encapsulates the pollutant and that during its firing it does
not produce the emission of harmful volatile elements. The
objective of this work was to perform both tests in a
ceramic paste made with slip-casting wastes and electroplating
residues. The leaching methods for determining the
encapsulation of potential harmful elements were performed
following the TCLP, EP-Tox norm. Having precise
chemical analysis of both crude and fired brick, the problem
of emissions losses during the firing can be solved by
the gain/loss techniques used in geological studies. In
particular, the Isocon method that permits a quick visualization
of the lost elements is useful. Once the volatile
elements were determined, their amount was calculated
considering a constant element and the chemical concentrations
normalized by the loss of ignition, or using the
crude/fired brick ratio densities. The leaching tests indicate
that the ceramic brick does not produce harmful leachates
according to Argentinean specifications. The leachates of B
and Ca are high. Ca does not seem to be a problem while
the B content is beyond the permitted limits. During the
firing, volatilized elements are Ag, Br, Cl, F, Hg, S, Se, and
H2O. The loss of Ag, Br, and Se are negligible. For F and
Cl the potential emission rate is very low (100 mg/kg)
while in the case of S, the 2,600 mg/kg rate is high.
However, extrapolated emission rates at the chimney
assuming an air-to-brick ratio of 2.5 N m3/kg, are
approximately 1,040 mg/N m3 for S and 40 mg/N m3 for F
and Cl, falling inside environmentally acceptable values.
The geochemical procedures proved to be useful tools to
assess the element mobilization during firing of ceramic
wares and in the analyzed case, the results indicate that the
paste is environmentally acceptable.2O. The loss of Ag, Br, and Se are negligible. For F and
Cl the potential emission rate is very low (100 mg/kg)
while in the case of S, the 2,600 mg/kg rate is high.
However, extrapolated emission rates at the chimney
assuming an air-to-brick ratio of 2.5 N m3/kg, are
approximately 1,040 mg/N m3 for S and 40 mg/N m3 for F
and Cl, falling inside environmentally acceptable values.
The geochemical procedures proved to be useful tools to
assess the element mobilization during firing of ceramic
wares and in the analyzed case, the results indicate that the
paste is environmentally acceptable.3/kg, are
approximately 1,040 mg/N m3 for S and 40 mg/N m3 for F
and Cl, falling inside environmentally acceptable values.
The geochemical procedures proved to be useful tools to
assess the element mobilization during firing of ceramic
wares and in the analyzed case, the results indicate that the
paste is environmentally acceptable.3 for S and 40 mg/N m3 for F
and Cl, falling inside environmentally acceptable values.
The geochemical procedures proved to be useful tools to
assess the element mobilization during firing of ceramic
wares and in the analyzed case, the results indicate that the
paste is environmentally acceptable.