ALUMINOTHERMIC FERRONIOBIUM OBTAINING METHOD Russian patent published in 2012 - IPC C22C33/04 

FIELD: metallurgy.

SUBSTANCE: at the first stage of the method the charge is loaded at the speed of 230-260 kg/m²min; it contains 10-11% of niobium concentrate of its mass for melting, iron scale of 16.0-19.0% of its mass for melting and aluminium in quantity of 0.92-0.99 of stoichiometrically required one for reduction of niobium - in the charge at the first stage. At the second stage there loaded and molten is niobium concentrate with loading speed of 14-20 kg/m²min in quantity of 26.5-40.5% of its mass for melting. At the third stage the charge is loaded and molten with loading speed of 250-420 kg/m²min, which contains 48.5-63.5% of niobium concentrate of its mass for heating, 17.5-24.5% of iron scale of its mass for heating and aluminium in quantity of 1.25-1.57 of the stoichiometrically required one for reduction of niobium in the charge of this stage. At the fourth stage the charge is loaded and molten with speed of 105-125 kg/m²min; it contains 56.5-66.5% of iron scale of its mass for heating, lime in quantity of 4-6.5% of mass of niobium concentrate for melting and aluminium 2.03-2.25 of stoichiometrically required one for reduction of niobium oxides in molten slag. After the charge is molten, it is heated under arcs of electric furnace during 0.15-0.25 of the charge melting time, and melting products are poured.

EFFECT: invention allows increasing the niobium extraction to the alloy and reducing specific aluminium flow for melting.

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