Method for smelting niobium-containing steel by using niobium concentrate

The invention discloses a method for smelting niobium-containing steel by using niobium concentrate. The method comprises the steps that converter blowing is carried out, molten iron and waste steel are subjected to oxygen blowing smelting in a converter, niobium concentrate and a reducing agent are added to the bottom of a steel ladle before tapping, a deoxidizing agent is added for deoxidation after tapping, argon is introduced into the bottom of the steel ladle in the tapping and deoxidizing agent adding process, and the flow of the argon is 500-800 NL/min; the molten steel obtained after converter blowing is refined, waste steel continues to be added after temperature rise, deoxidation treatment and desulfurization treatment are conducted, the components of the molten steel are adjusted, in the refining step, the temperature of the molten steel is adjusted through electrode heating, argon is introduced for stirring, and the flow of the argon is 200 NL/min to 800 NL/min. According to the method, the steel