To obtain the primary aluminum, the industries use the
reduction process which is constituted by the extraction of metal (aluminum)
from its oxide (alumina). The Hall-Héroult process is used for alumina
reduction by the use of graphite anodes even though it involves a high emission
of carbon dioxide (CO2) and several other organic compounds. Proposals have
been made aiming at substituting graphite for a single-phase SnO2-based ceramic
with low resistivity and chemical resistance to cryolite, which is
characterized as an inconsumable anode, reducing pollutant emissions. To this end,
a wide range of studies was carried out on SnO2-based ceramics modified with
ZnO as a densification aid doped with the promoters of electrical conductivity
such as Nb2O5, Al2O3 and Sb2O3 through a mixture of oxides and hybrid sintering
in a microwave oven. The pressed pellets were sintered in a microwave oven up
to 1050ºC under a constant heating rate of 10ºC/min. The morphology of the
ceramic compacts was analysed by field emission scanning electron microscopy
(FE-SEM—JEOL Model JSM 7500F) coupled with energy-dispersive X-ray spectroscopy
(Thermo Scientific, Noran System 7). After sintering, the density was
determined by the Archimedes method, the phases were then characterized by
X-ray diffraction. The microstructure and chemical composition resulting from
the sintered SnO2-based ceramics were also investigated by field emission
scanning electron microscopy (FE-SEM) coupled with energy-dispersive X-ray
spectroscopy (EDS). Electrical properties were determined by the measurements
of the electric field-current density. A single-phase ceramic was obtained with
a relative density of above 90% and electrical resistivity of 6.1\(\Omega\).cm
at room temperature. The ceramics obtained in this study could be a potential
candidate as an inconsumable anode to replace the current fused coke used in
the reduction of alumina. In addition to its material properties, this approach
reduces carbon emissions, due to the process reduction of time and temperature,
aligning with sustainable development goals.
Author(s) Details
Perazolli, L.
Interdisciplinary Laboratory of Electrochemistry and
Ceramics – LIEC, Institute of Chemistry, Paulista State University “Júlio
Mesquita Filho” (UNESP), Rua Prof. Francisco Degni, 55, Quitandinha, 14800-060,
Araraquara - SP, Brasil.
Gasparotto, Gisane
Interdisciplinary Laboratory of Electrochemistry and
Ceramics – LIEC, Institute of Chemistry, Paulista State University “Júlio
Mesquita Filho” (UNESP), Rua Prof. Francisco Degni, 55, Quitandinha, 14800-060,
Araraquara - SP, Brasil.
Jacomaci, N.
Interdisciplinary Laboratory of Electrochemistry and
Ceramics – LIEC, Institute of Chemistry, Paulista State University “Júlio
Mesquita Filho” (UNESP), Rua Prof. Francisco Degni, 55, Quitandinha, 14800-060,
Araraquara - SP, Brasil.
Ruiz, M.
Interdisciplinary Laboratory of Electrochemistry and
Ceramics – LIEC, Institute of Chemistry, Paulista State University “Júlio
Mesquita Filho” (UNESP), Rua Prof. Francisco Degni, 55, Quitandinha, 14800-060,
Araraquara - SP, Brasil.
Zaghete, M. A.
Interdisciplinary Laboratory of Electrochemistry and
Ceramics – LIEC, Institute of Chemistry, Paulista State University “Júlio
Mesquita Filho” (UNESP), Rua Prof. Francisco Degni, 55, Quitandinha, 14800-060,
Araraquara - SP, Brasil.
Foschini, C. R.
Interdisciplinary Laboratory of Electrochemistry and
Ceramics – LIEC, Institute of Chemistry, Paulista State University “Júlio
Mesquita Filho” (UNESP), Rua Prof. Francisco Degni, 55, Quitandinha, 14800-060,
Araraquara - SP, Brasil.
Aguiar E.C.
Interdisciplinary Laboratory of Electrochemistry and
Ceramics – LIEC, Institute of Chemistry, Paulista State University “Júlio
Mesquita Filho” (UNESP), Rua Prof. Francisco Degni, 55, Quitandinha, 14800-060,
Araraquara - SP, Brasil.
Varela, J. A.
Interdisciplinary Laboratory of Electrochemistry and Ceramics
– LIEC, Institute of Chemistry, Paulista State University “Júlio Mesquita
Filho” (UNESP), Rua Prof. Francisco Degni, 55, Quitandinha, 14800-060,
Araraquara - SP, Brasil.
Please see the book here:- https://doi.org/10.9734/bpi/cmsdi/v9/3850
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