PURPOSE: To make sepn. and discharge of slag automatic and the sepn. thorough by forming a spout which is formed with discharge ports at both ends and receives a molten metal in such a way that the inclination thereof can be adjusted and providing a gate for separating the slag on the metal discharge port side of the spout.

CONSTITUTION: A separating apout 3 is pivotally supported tiltably by means of a stanchion 8 on approximately the central side in the longitudinal direction thereof. A molten metal discharge port 5 is formed at one end and a slag discharge port 6 is formed at the other end. A gate member 4 is attached apart from the bottom of the spout in the spout 3 near the port 5. The tilting device for the spout 3 is constituted by, for example, a cylinder device 7. The molten metal in the melting furnace is thereupon tapped to approximately the central part of the spout 3 from a tap hole 2 of the melting furnace. The slag 14 in the molten metal floats on the molten metal 15 in the spout. The metal 15 flows out through the port 5 by passing underneath the member 4 but the slag 14 is blocked by the member 4 and is discharged through the port 6. The height of the ports 5, 6, i.e., the inclination of the spout 3 is adjusted by the device 7 according to the amt. of the molten metal, the separating condition of the slag and the metal, etc. so that the metal 15 does not flow out through the port 6.