Use of Secondary Alumina-graphite as Raw Material of Alumina-graphite Silicon Carbide Refractories
University of Orleans and CEMHTI/CNRS, 45071 Orléans Cedex 2/France
Revision 10.02.2013, 11.04.2013
Volume 5, Issue 3, Pages 97-100
Abstract
This paper discusses the possibilities to use spent alumina-graphite isostatic refractories (submerged nozzle, shroud, stopper) as a component of the raw material mix for the design of alumina-graphite silicon carbide used for torpedo ladles. Different approaches were carried out to quantify the key parameters and to optimise the recycling process: • sorting, cleaning and crushing of Al2O3-C continuous casting products • investigation of secondary raw materials: size distribution, microstructure, chemistry composition and mineral phases • design of alumina-silicon carbide-graphite bricks containing recycling alumina-graphite raw materials • characterisation of the recipes and evaluation of their properties (chemistry composition; physical properties, mineralogy, microstructures) • evaluation of oxidation resistance and corrosion resistance of the products. The challenge is to develop new alumina-graphite silicon carbide refractories containing secondary alumina-graphite raw materials. The use of spent alumina graphite refractory material is restricted by the need to elaborate Al2O3-C-SiC high quality products that needs strict specifications. Consequently the amount of recycling raw materials was limited to 30 mass-%. In this case, the characteristics of alumina-graphite silicon carbide recycling refractories are similar to the usual qualities.
Keywords
recycling, Al2O3-C secondary raw materials, Al2O3-C-SiC refractories, torpedo ladles
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