Lid for electric arc furnaces comprises a lower layer made of stone facing the metal melt, an upper layer made of a monolithic composition, and a collar encompassing the upper and lower layers

摘要

Furnace lid comprises: a lower layer (28) made of stone facing the metal melt with a middle part connecting a base part and a head part; an upper layer (40) made of a monolithic composition filling open regions between the head and middle parts and covering the head part; and a collar encompassing the upper and lower layers. Preferred Features: The base part, middle part and head part run concentrically to a common longitudinal axis of the stone. The head part has a smaller cross-sectional surface than the base part. The stone in the peripheral region of the base part has a covering (24) which can be removed under the action of heat. The monolithic composition neighboring the collar extends up to the plane of the free end of the base part. The covering is made of a combustible material such as cardboard, plastic or a lacquer.