This invention relates to a refractory product for use in continuous casting. More particularly the invention is concerned with tubular refractory products for use in pouring of melt from the tundish to the mould. Flow of melt from the tundish into a mould is commonly controlled by raising or lowering of a refractory stopper rod from or to a seating position in the base of the tundish where there is located either a fixed sub-entry nozzle (SEN) or a tundish nozzle, built into the tundish base, onto which a sub entry shroud (SES) is fastened. In place of stopper rod valve closures, a slide gate control mechanism to which the SEN or SES is attached is also known.
Recently some steelmakers have been fitting to the underside of thethe joints reacts with the alumina in the steel leading to build up of alumina deposits and clogging of the pouring tube. Such reaction also yields a problem manifesting itself as inclusions in the casting commonly identified as black spot.
Thus those in this field have hitherto sought to mitigate such problems by seeking to improve the tube handling and change-over systems leading to ever more complex and expensive handling systems.