Abstract: The invention relates to a device for the treatment of a stream of aluminum or magnesium-based liquid metal or alloy during its passage, comprising a ladle formed by an external metal casing, a refractory lining, a channel for the admission of the crude liquid metal at the rear, a nozzle for the casting of the treated liquid metal at the front, at least one internal partition leaving, with the bottom of the ladle, a space for the circulation of the liquid metal and defining a first rear compartment and at least one second front compartment opening into the casting nozzle. The ladle is fixed on a supporting cradle connected to an articulated frame relative to which the said cradle can rock forwards about a first horizontal axis passing through the casting nozzle, the articulated frame itself being connected to a fixed frame relative to which it can rock about the second horizontal axis. The first horizontal axis is approximately perpendicular to the stream of liquid metal.