METHOD FOR REFINING MOLTEN FE-NI ALLOY

• Main Author: MUKAI TAKASHI
• Format: Patent
• Language: English
• Published: 04.06.1996
• Edition: 6
• Subjects: CHEMISTRY; CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION ORPROCESSING OF GOODS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; METALLURGY; METALLURGY OF IRON; PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OFWROUGHT-IRON OR STEEL; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS

PURPOSE: To refine molten metal having low C and S without occurring any carbon pickup problem and necessitating any reformation of produced slag. CONSTITUTION: In the refining method of molten Fe-Ni alloy, the molten Fe-Ni metal containing at least 30-50wt.% Ni is pre-refined into <=0.01% carbon content under vacuum or low oxygen partial pressure atmosphere in a vessel 5 having a heating device by pouring the molten Fe-Ni metal into the vessel 5 or by melting the solid raw material in the vessel. Successively, slag-making agent mainly consisting of CaO is added into the molten metal and heated with a gas plasma and re-refining is executed to make the molten metal <=0.01% carbon and <=0.05% sulfur. The vessel for the re-refining may be executed in the separated vessel and the means for pre-refining the molten metal so as to be <=0.01% carbon content may be executed by blowing gaseous oxygen.