| 摘要 |
PROBLEM TO BE SOLVED: To prevent a dissolution of fluorine into drainage by stabilizing the fluorine in slag by using flux containing lime and an iron oxide or gaseous oxygen to dephosphorize molten iron and specifying the fluorine wt. and lime wt. to the dephosphorizing quantity in this dephosphorizing flux. SOLUTION: Molten iron containing desirably 0.05-0.25% Si, is dephosphorized by using flux containing lime and slag containing fluorine as a part, iron oxide and/or gaseous oxygen, and the [P] concn. in the molten iron after treatment is made to >=0.03% and CaO/O is made to 0.2-0.8. In this phosphorizing method of the molten iron, to the dephosphorizing quantityΔP% before and after treatment, the fluorine wt. is made to <=6×ΔP kg/ton and the lime wt. is made to 25×ΔP-55×ΔP kg/ton in the dephosphorizing flux and desirably,ΔP is made to >=0.07%. In this way, the fluorine in the slag is formed as the extremely stable fluorapetite to prevent the elution into the drainage.
|
