SUCKING AND REMOVING METHOD FOR SLAG IN MOLTEN IRON TREATMENT

摘要

PURPOSE:To facilitate slag-off by a suction type slag cleaner for formed slag in divided refining of molten iron by adding the waste slag of a desiliconization (de-Si) treatment at the proper timing of dephosphorization (de-P) or simultaneous desulphurization (de-S) and de-P treatments thereby forming slag. CONSTITUTION:In divided refining of molten iron, the molten iron is subjected to slag-off after a de-Si treatment, in succession to which it is subjected to slag off after a de-P treatment or simultaneous de-S and de-P treatment. The treated slag of the latter has high basicity, low T.Fe and poor fluidity. On the other hand, the amt. of SiO2 in the treated slag of the former is extremely large. Therefore, the waste slag of the de-Si treatment is added to the molten iron at the end period of the de-P treatment of the simultaneous de-S and de-P treatments or upon completion of the treatments or at a proper time from the last period of the treatments till the end of the treatment, whereby the slag is formed. In this way, the slag-off is accomplished with a suction type slag cleaner by reducing the basicity of the slag and improving its fluidity.