GB1011056A - Improvements in or relating to the degasification of metal - Google Patents

Abstract

Metal is melted in a furnace without the application of vacuum and is tapped into a launder which conveys it directly to a receiver mounted on a vacuum vessel, the latter either containing or constituting a ladle, and the capacity of the latter vessel being substantially greater than that of the receiver. The metal is subjected to a stream degassing treatment during its passage from the receiver into the ladle, and is then cast, either in air or in a <PICT:1011056/C6-C7/1> <PICT:1011056/C6-C7/2> protective gas. Alloying or deoxidizing additions such as Ti, Nb, B or Al may be made to the metal while in the vacuum chamber; desulphurization may also be effected by the addition of suitable agents such as a mixture of lime and fluorspar to the ladle before or during tapping. The line connecting the vacuum vessel to the pump may be flexible and may be equipped with cooling sprays. In the embodiment of Fig. 1, the vacuum vessel consists of a ladle 1 having cover 2 fitted with receiver 5, means 11 for making additions and television camera 12. Metal is discharged directly from the furnace through launder 16 to receiver 5, slag being removed through overflow launder 14. In the modification shown in Fig. 5, ladle 46 is located within vacuum vessel 41 having cover 2 hinged at 60. Receiver 47 is provided with bracket 49 carrying guiding means 50 for launder 51, which is connected to tapping spout 52 by links 53.