| 摘要 |
<PICT:1082413/C6-C7/1> Apparatus for de-gassing molten metal consists of an evacuated vessel into which the metal is drawn through an inlet tube and from which it leaves through a discharge nozzle into a second de-gasification chamber. The treated metal may then be discharged, as to a continuous casting plant, or may be returned to the original receptacle. As shown in Fig.2, metal is caused to rise from ladle 6 into first vacuum chamber 1, possibly aided by electromagnetic pump 17' or lift gas from pipes 23, 25, and passes from there to second chamber 5. It may then be returned to ladle 6 by pipe 16 or 16', or discharged to continuous casting mould 8. The rate of flow to the mould may be controlled by adjusting the rate of return to ladle 6 by means of pump 17. The plant may be used to decarburize molten steel, in which case oxygen or an oxygen-containing gas such as CO2 may be used as the lift gas, or a low pressure of oxygen may be maintained in one or both of the vacuum chambers; alternatively unwanted elements such as copper, lead, tin, zinc, bismuth, antimony, cadmium or arsenic may be volatilized, aided possibly by the use of halogen or halogen compound as a lift gas. By recirculating the metal more than one treatment may be carried out. Alloying additions may be made to the steel while it is passing through one or other of the vacuum chambers. |
