Control method of boron content in refining process of acid slag produced in silicon killed steel production

The invention discloses a control method of boron content in the refining process of acid slag produced in silicon killed steel production. The control method includes the steps of firstly, molten steel is subjected bessemerizing and tapping, silicon iron and ferromanganese are added in the tapping process to perform deoxidization alloying, low-nitrogen carbon powder is added according to tappingcarbon content, a final slag modifier is added, and a tapping end point adopts slag-stopping tapping; secondly, after LF furnace slag temperature rise, 0.17-0.35kg of silicon iron is added into each ton of steel to perform slag top deoxidization; 2-4kg of lime is added into each ton of steel to produce high-alkalinity reducing slag, FeO and MnO in the slag is not more than 2.0%, and the alkalinityof the slag is not smaller than 2; thirdly, alloy is regulated according the components of refined molten steel, quartz sand is added to regulate the alkalinity to be not larger than 1.2, soft blow is performed for 15-20 minu