A sound refractory that has been properly installed, sintered and maintained, plus operator diligence to prevent a dangerous bridge from forming, are key to minimizing metal run-out. The physics of electrical induction requires the refractory lining between the induction coils and the bath to be as thin as possible. At the same time, it must be thick enough to fully protect the coils and prevent metal run-out during attacks by molten metal, chemical agents, and mechanical shocks

Metal run-out ranks among the most severe accidents that can occur during melting and holding operations. Runouts occur when molten metal breaks through the furnace lining. If cooling, electrical, hydraulic or control lines become damaged, there is danger of a fire or water/molten metal explosion. Maintaining furnace lining integrity is key to preventing a run-out. Such integrity can be compromised by:

• Installation of the wrong refractory material for a particular application.
• Inadequate or improper installation of refractory material.
• Improper sintering of the refractory material.
• Failure to monitor normal lining wear and allowing the lining to become too thin.
• The sudden or cumulative effects of physical shocks or mechanical stress.
• The sudden or cumulative effects of excessive temperatures or thermal shocks.
• Slag or dross buildup.