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SnO2 ceramic with low resistivity

Grant number: 11/01161-2
Support type:Scholarships in Brazil - Scientific Initiation
Effective date (Start): April 01, 2011
Effective date (End): November 30, 2013
Field of knowledge:Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
Principal Investigator:Leinig Antonio Perazolli
Grantee:Natalia Jacomaci
Home Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
Associated scholarship(s):12/18066-5 - Electron microscopy to obtain for kinetic microwave sintering of ceramics SnO2-modified ZnO, BE.EP.IC

Abstract

Aluminum production is the reduction of Al and Al2O3 in CO2 in molten cryolite bath in an electrochemical cell-type Hall-Heroult with graphite anode. The problems due to this process are the release of carbon dioxide, high power consumption, high consumption of the anode and the formation of impurities due to reaction with graphite. Clark (1), Alder (2, 3) and Hansey (4) inconsumable patented electrode based on SnO2 doped with CuO and Sb2O3 and obtained resistivity of 0.0025 ©.cm to 975°C. In this project, the composition used in the patent Clark (2) is reproduced for comparison of results, are also produced new ceramic electrodes based on SnO2 inconsumable modified with ZnO, Nb2O5, Al2O3 and Sb2O3. These ceramics are tested in order to obtain a ceramic with high density (> 95%) and low resistivity (Ã <1 ©.cm). The ceramic powders are obtained by the traditional method of mixed oxide, characterized by TG / DTA, X-ray diffraction (XRD), surface area by BET method (ASAP), then the ceramic powder will be conformed into a cylindrical shape with 12mmX2mm, sintered in a dilatometer and in furnace, both the temperature up to 1400°C and ultra-fast heating (microwave) until the temperature of 1050ºC with heating rates of 10°C/min. and 50°C/min. respectively. After sintering density tests must be made of Archimedes, scanning electron microscopy (FEG / SEM-EDS), voltage-current measurements at room temperature and impedance spectroscopy measurements.