Patent GB-631813-A (GB)
Title: Process for the manufacture of artificial carbon bodies
IPC: C04B35/532
Filed: 1946-12-20
Abstract: Carbonaceous composition pieces for electrodes or shaped blocks for metallurgical furnaces are produced in an electric resistance baking furnace in which heat is internally generated by electric current passing through a carbonaceous filling powder, e.g. coke or mixtures of coke with bauxite, graphite, anthracite or alumina, by moulding the carbonaceous mass composed substantially of carbon, e.g. ground coke, and binder, e.g. coal tar pitch, to its final shape in the body of the filling powder and baking the mass without any change of position.  Preferably the carbonaceous mass is initially in a warm (140-200 DEG  C.) pasty state after preliminary mixing and kneading, and the moulded pieces are packed to such a height, say at least 50 cms., in the furnace that a substantial temperature difference occurs between upper and lower layers causing baking to proceed from bottom to top, which baking may continue to complete graphitization.  The filling powder has spaces made to receive the carbonaceous mass for instance by placing frames, e.g. sheet metal such as iron, or thin wood or cardboard, having sides but no bottom on the furnace hearth, which is covered with a layer of filling powder, and filling the interstices with filling powder.  The pasty mass is poured into the frames, which are removed, and the whole covered with a layer of filling powder before baking.  The frames may be wrapped or lined with paper before pouring to prevent sticking and to give a hard outer shell to the pieces, which may also be grooved or morticed by inserting wood blocks in the correct position.  The carbonaceous mass may be subjected to high frequency vibrations before or after pouring.  Specification 561,496, [Group V], is referred to.  The Specification as open to inspection under Sect. 91 comprises also the use of a previously bricquetted mass for placing in the baking furnace.  This subject-matter does not appear in the Specification as accepted.ALSO:Carbonaceous composition pieces for electrodes or shaped blocks for metallurgical furnaces are produced in an electric resistance baking furnace in which heat is internally generated by electric current passing through a carbonaceous filling powder, e.g. coke or mixtures of coke with bauxite, graphite, anthracite or alumina, by moulding the carbonaceous mass composed substantially of carbon, e.g. ground coke, and binder, e.g. coal tar pitch to its final shape in the body of the filling powder and baking the mass without any change of position.  Preferably the carbonaceous mass is initially in a warm, 140 - 200 DEG  C., pasty state after preliminary mixing and kneading, and the moulded pieces are packed to such a height, say at least 50 cms., in the furnace that a substantial temperature difference occurs between upper and lower layers causing baking to proceed from bottom to top, which baking may continue to complete graphitization.  The filling powder has spaces made to receive the carbonaceous mass for instance by placing frames, e.g. sheet metal such as iron, or thin wood or cardboard, having sides but no bottom on the furnace hearth, which is covered with a layer of filling powder, and filling the interstices with filling powder.  The pasty mass is poured into the frames, which are removed, and the whole covered with a layer of filling powder before baking.  The frames may be wrapped or lined with paper before pouring to prevent sticking and to give a hard outer shell to the pieces which may also be grooved or morticed by inserting wood blocks in the correct position.  The carbonaceous mass may be subjected to high frequency vibrations before or after pouring.  Specification 561,496 is referred to.  The Specification as open to inspection under Sect. 91 comprises also the use of a previously briquetted mass for placing in the baking furnace.  This subject-matter does not appear in the Specification as accepted.