Process for dephosphorization and denitrification of chromium-containing pig iron
AssigneeNisshin Steel Co., Ltd.
InventorsShigeaki Maruhashi, Morihiro Hasegawa, Takashi Yamauchi
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Abstract
A process for dephosphorization-denitrification of Cr-containing pig iron by oxidizing refining is disclosed. Said process comprises maintaining the Si content of the molten iron at not more than 0.2%, contacting it with a slag comprising at least one of fluorides and chlorides of alkaline earth metals, at least one of lithium oxide and carbonate, and at least one of oxides of iron and nickel, while controlling oxidation of Cr.
Claims14
A process for dephosphorization-denitrification of molten pig iron containing not less than 3% of Cr, comprising maintaining the Si concentration of said molten pig iron at 0.2% by weight or less, contacting said pig iron with a slag comprising 30-80% by weight of at least one selected from fluorides and chlorides of alkaline earth metals, 0.4-30% by weight of at least one selected from lithium oxide and lithium carbonate, and 5-50% by weight of at least one of iron oxides and nickel oxide, said slag may contain less than 40% by weight of at least one selected from oxides and carbonates of alkaline earth metals, while controlling oxidation of Cr.
Dependencies are inferred from the claim text.