PROCESSES FOR REFINING NIOBIUM-BASED FERROALLOYS

Refined niobium-based ferroalloys are provided by removing lead and other impurities therefrom by a process comprising charging niobium ore concentrate and/or niobium oxide or a mixture of niobium oxides to a metallothermic reaction chamber, admixing the ore concentrate and/or niobium oxide with a r...

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Bibliographische Detailangaben
Hauptverfasser:	Sernik, Kleber A, Sousa, Clovis Antonio De Faria, Ribeiro, Eduardo Augusto Ayroza Galvão
Format:	Patent
Sprache:	eng
Schlagworte:	ALLOYS CHEMISTRY FERROUS OR NON-FERROUS ALLOYS METALLURGY PRETREATMENT OF RAW MATERIALS PRODUCTION AND REFINING OF METALS TREATMENT OF ALLOYS OR NON-FERROUS METALS
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Beschreibung
Zusammenfassung:	Refined niobium-based ferroalloys are provided by removing lead and other impurities therefrom by a process comprising charging niobium ore concentrate and/or niobium oxide or a mixture of niobium oxides to a metallothermic reaction chamber, admixing the ore concentrate and/or niobium oxide with a reducing agent, initiating a metallothermic reaction, under reduced pressure; and allowing the reaction product to solidify and cool; crushing the reaction product or crushing the niobium-based ferroalloy previously reduced in open air, and charging the crushed product to a melting crucible within a vacuum induction melting furnace, lowering the pressure within the furnace to below 1 mbar, and melting the crushed product while vaporizing the impurities contained therein.