A retort, used in the Bessemer process, in which molten cast iron is decarburized and converted into steel by a blast of air forced through the liquid metal.

a furnace in which the pyrochlore concentrate is converted into ferroniobium and heat is produced by the oxidation reaction.

A furnace in which a gas, usually air, is blown through the molten bath or crude metal for the purpose of oxidizing impurities.

In copper smelting, a furnace used to separate copper metal from matte.

A brick-lined, cylindrical vessel in the smelter for processing molten copper matte from the reverberatory furnace; the impurities, principally iron and sulphur, are removed by blowing air through the molten bath; the result is blister copper (97% purity).