An internal lining for protecting the permanent refractory lining of a metallurgical vessel (1, 2) such as a tundish, casting ladle or slag pot has a base of refractory inorganic particles coated with a binder. The protective internal lining is constituted by at least two layers, namely an inner layer (3) which sinters throughout its mass under the action of heat of the molten metal contained in the metallurgical vessel, and a layer (4 or 5) which does not sinter at all or sinters only to a partial extent in order to remain friable even when the inner layer (3) has completely sintered.