Molten iron desulfuration slag spray modification process

The invention discloses a molten iron desulfuration slag spray modification slag process, comprising the following steps: spraying a modifier into the deep part of the molten iron adopting gas delivery through a spray gun inserted into the molten iron in a molten iron tank, wherein, the spray amount of the modifier in per ton of the molten iron is 0.5-2.5kg; and realizing the full modification of the desulfuration slag through the reaction of the modifier and the desulfuration slag floated on the surface of the molten iron. By utilizing the modification process, the desulfuration slag modifier is sprayed into the deep part of the molten iron through the spray gun; in the floating process of the modifier, as static pressure is reduced continuously, the sprayed bubble is continuously swollen; and the spreading dispersion of the modifier is promoted; after reaching the surface of the molten iron, the modifier is contacted with the thin-layer rare slags on the surface of the molten iron to react, thus realizing the full modification of the modifier on the thin-layer rare slags; and the integrated mixing of the modifier and the desulfuration slag is realized through the drastic fluctuation of the liquid surface in the spray process, thus achieving the purpose of the integrated modification of the desulfuration slag.