Smelting method of ultralow-phosphorus stainless steel mother liquor

The invention discloses a smelting method of ultralow-phosphorus stainless steel mother liquor, which comprises the following steps: melting high-phosphorus nickel pig iron in an intermediate frequency furnace at the tapping temperature of 1500-1550 DEG C, the electric quantity of 14000-16000 kwh and the tapping quantity of 30-35 tons; the molten high-phosphorus nickel pig iron is added into an AOD furnace to smelt ultralow-phosphorus stainless steel mother liquor, the oxygen flow is 4000-4500 m < 3 >/h, the nitrogen flow is 600-1000 m < 3 >/h, and 10% of high-phosphorus nickel pig iron cold materials are added in the process; 2-4 tons of lime is added in batches in the smelting process for slagging, and the target alkalinity is controlled to be 4.0-5.0; when oxygen blowing reaches 1000-1500 m < 3 > and the temperature is 1550-1600 DEG C, oxygen blowing is stopped, 500-800 kg of fluorite is added to adjust the fluidity of the slag, and slagging-off is conducted after blowing is conducted for 5-8 minutes at th