摘要 |
In order to obtain a ladle stopper made of refractory concrete having improved qualities of use and a longer service life, a ring (9) made of prefabricated refractory concrete is laid into the casting mould (1) so as to concentrically surround the draining channel (6), the casting mould is then filled with pasty refractory concrete (4), the cast mass is compressed, dried and impregnated under pressure with a carbon carrier. The carbon carrier that impregnates the sealing surface of the ladle stopper in then cracked by a thermal treatment in a reducing atmosphere so as to crack the carbon. If required, one or several negative pressure treatments may be applied during the production process. By laying the prefabricated ring (9) into the mould and realizing the disclosed process steps, the sliding surface of the stopper brick gains remarkable qualities of use, and at the same time the prefabricated ring can compensate increased thermal stresses in the area of the draining channel (6). |