Coarse smelting device and direct steelmaking system and method applying same

The invention relates to a primary smelting device and a direct steelmaking system and method applying the primary smelting device, and belongs to the technical field of metallurgy. The primary smelting device comprises a first smelting area and a second smelting area which are directly connected; the direct steelmaking system comprises a middle storage bin of the direct reduction device, a conveying system, a primary smelting device and a refining device. The direct steelmaking method comprises the steps that metallized pellets obtained through reduction in a direct reduction device are added into a first smelting area to be heated and molten, molten product slag and molten iron are obtained, and the slag is discharged through a slag outlet at regular intervals; molten iron serving as a melt separation product naturally flows to a second smelting area by virtue of gravity for decarbonization, dephosphorization and desulfurization refining, so that crude molten steel is obtained; and adding the crude molten s