| 摘要 |
<p>In a process of desulphurizing pig iron by means of a desulphurizing slag under strong reducing conditions, a gas is passed into the molten mass in a closed, unfired vessel in such quantity, not less than four times the volume of the iron, and with such provision for the escape of excess gas, that carbon monoxide is continuously discharged from the vessel with consequent reduction of the partial pressure of oxygen at the iron slag interface. The gas used may be hydrogen, nitrogen, a mixture of hydrogen and nitrogen or blast furnace gas treated to remove CO, or CO and CO2, and the amount of CO present should never exceed 40 per cent. A layer of slag comprising lime, fluorspar and blast furnace slag may be supported on the metal in a rotatable vessel lined with a carbon refractory and the stream of gas not exceeding sixteen times the volume of iron passed through at least half the depth of metal and slag. The amount of sulphur remaining in the iron depends on the volume of gas used and it is stated that 0.003 per cent S may be obtained. Specification 499,302 is referred to.</p> |
