Converter final slag thickening method

The invention discloses a converter final slag thickening method. The converter final slag thickening method includes the steps that firstly, after oxygen is blown for 10 minutes, gun pressing operation is conducted, in other words, the position of the gun is reduced by 200 mm, the oxygen pressure is kept between 0.75 MPa and 0.80 MPa, and duration is larger than 40 seconds; secondly, through a sampling laboratory test, and when the carbon content of molten steel is higher than the requirement of a smelting steel grade or the temperature of the molten steel is lower than the requirement of the smelting steel grade, reblowing treatment is conducted; thirdly, raw dolomite or lime is added so as to serve as a thickening material before steel is placed, and the addition amount of steel ranges from 2 kg/t to 5 kg/t. Through the optimization of converter end point gun pressing and reblowing, the FeO content of furnace slag is reduced, the metal yield is increased, the slag blocking success rate can be increased, the steel ladle slag amount is reduced, rephosphorization is reduced, the splashed slag furnace protecting effect can be improved, the furnace age can be prolonged, the slag amount requirement for slag residual operation is guaranteed, and lime consumption can be reduced.