Steel plant term for patching the hearth, banks and slag line of an electric arc or open hearth furnace between heats, by shoveling, throwing or machine-gunning granular dolomite or magnesia onto worn spots while the furnace is hot. Regular fettling keeps the banks built up and extends hearth life. In foundries the same word means cleaning sand and fins off castings, a completely different job.
Fettle the slag line banks after this tap, the left bank's getting thin by the door.
Also heard as
- fettle
- bank repair
Related terms
Gunning
Spraying refractory through a hose and nozzle with compressed air to build or repair a lining.
Dead-burned magnesia
Magnesia fired so hard it barely reacts with water, the main raw material of basic refractories.
Slag line
Band of a ladle or furnace lining where the slag layer floats on the metal, usually the fastest-wearing zone.
Basic refractory
Refractory based on magnesia, lime or dolomite that resists basic slags with high lime-to-silica ratios.