Method for reducing nitrogen increase of molten steel in refined-smelting ladle furnace (LF) in heating process

• Main Authors: ZHAO CHENGUANG, ZHANG YUE, MEI XUEHUI, LIN YANG, WU CHUNJIE, SUN QUN, ZHANG ZHIWEN
• Format: Patent
• Language: Chinese; English
• Published: 30.01.2013
• 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

The invention provides a method for reducing nitrogen increase of molten steel in a refined-smelting ladle furnace (LF) in a heating process. The center of each of three electrodes is provided with an argon hole, the circumference of the lower edge of a furnace cover is provided with an argon ring pipe provided with argon blowing holes, and the argon holes and the argon ring pipe are respectively connected through a gas inlet hose and an argon pipeline. In the molten steel treatment process of the LF, argon is blown into the furnace respectively through the electrode argon holes and the argon blowing holes in the argon ring pipe. In the heating process of the LF, the speed of a dust removal blower is reduced to 30-70% of the normal speed, and foaming white lime is added to molten steel by 1-3 batches, wherein 1-3kg of foaming white lime is added to every ton of molten steel for each batch. The invention can control the nitrogen increase mass percent of molten steel for one minute on average in the heating pro