0353氮化硅结合碳化硅材料在电解.pdfVIP

Spent Si3N4 Bonded SiC Sidelining Materials in Aluminium Electrolysis Cells Zh. Wang1, E. Skybakmoen2, T. Grande1,3 1Department of Materials Science and Engineering, Norwegian University of Science and Technology, N-7491Trondheim, Norway 2SINTEF Materials and Chemistry, N-7465Trondheim, Norway 3 Corresponding author: tor.grande@material.ntnu.no Keywords: Aluminium Electrolysis, Sidelining, Degradation, Si3N4-SiC Abstract Fabrication Si3N4 bonded SiC sidelining materials with different ages in Si3N4 bonded SiC sidelining blocks are commonly produced by operation have been analyzed by X-ray diffraction, electron using a mixture of silicon carbide grains and finely divided microscopy and chemical analysis. The chemical degradation of (typically 325 mesh) elemental silicon and a binder. The block the upper and the lower part of the sidelining has been can be formed into shapes via slip casting, vibratory casting, or by demonstrated to be substantially different. The upper part of the pressing. The green blocks are fired in a furnace in an air sidelining has been subjected to oxidation by the pot gas and the atmosphere at low temperature (up to 300oC) and then in a main degradation product found was Si2ON2. The lower part was nitrogen atmosphere at temperatures below the melting point