The durability of acoustically tested SP-11-type mullite-corundum stoppers

An investigation carried out at the Novolipetsk Metallurgical Plant of the performance of the SP-11-type mullite-corundum stoppers produced by the Semiluk Refractories Plant showed that the durability was highest in the case of stoppers with a resonance frequency of 10,000–12,000 Hz. The stoppers falling into that frequency range account for about 70% of the total output.