Molten and cast refractory product with a high zircon content and improved electrical resistivity suitable for use in glass melting furnaces producing high quality glass for LCD flat screens

摘要

#CMT# #/CMT# Molten and cast refractory product with a high zircon content, contains (by wt.% on an oxide base and a total of more than 98.5%) : (a) zircon (ZrO2) + hafnium oxide (Hf2O) greater than 85; (b) Silica (SiO2) : 2 to 10; (c) Alumina (Al2O3) : 0.1 to 2.4; (d) Boron oxide (B2O3) less than 1; (e) a doping agent chosen from vanadium oxide (V2O3), chromium oxide (CrO3), niobium oxide (Nb2O5), molybdenum oxide (MoO3), tantalum oxide (Ta2O5), tungsten oxide (WO3) and their mixtures to a given overall quantity and relationship. #CMT# : #/CMT# An independent claim is also included for a glass melting furnace incorporating this refractory product. #CMT#USE : #/CMT# Refractory product is used for the construction of glass melting furnaces. #CMT#ADVANTAGE : #/CMT# Provides a refractory material with an improved electrical resistivity, notably of at least 200 omega .cm at 1500 [deg]>C, whilst conserving a good resistance to corrosion by molten glass. This ensures that it can be used for the construction of glass melting furnaces for the production of high quality glass, in particular for the subsequent fabrication of LCD flat screens. #CMT#CERAMICS AND GLASS : #/CMT# The relationship for the doping agent additions is such that: 0.2% = 2.43.V 2O 5 + 8.84.CrO 3 + 1.66.Nb 2O 5 + 6.14.MoO 3 + Ta 2O 5 + 3.81.WO 3 (claimed). The doping agent content may be greater than or equal to 0.6% and/or less than or equal to 3% or preferably 1.4% (claimed). The refractory product may also contain yttrium oxide (Y 2O 3) in a quantity of less than or equal to 1% (claimed).