Covering slag for smelting low-carbon steel in intermediate frequency furnace as well as preparation method and application of covering slag

The invention belongs to the technical field of steel smelting, and particularly relates to covering slag for smelting low-carbon steel in an intermediate frequency furnace and a preparation method and application thereof. According to the technical scheme, the covering slag for smelting the low-carbon steel in the intermediate frequency furnace is prepared from, by mass, 20-22 parts of sodium chloride, 14-16 parts of potassium chloride, 18-20 parts of limestone, 16-20 parts of silicon dioxide, 10-12 parts of bauxite and 12-16 parts of calcium silicate, and the preparation method comprises the steps that the sodium chloride, the potassium chloride, the limestone, the silicon dioxide, the bauxite and the calcium silicate are ground and mixed; and adding water to prepare blocks and drying to obtain the covering slag. And after the intermediate frequency furnace melts the molten steel, covering the covering slag on the steel ladle. A protective film is formed on the surface of the molten steel to isolate contact