A method for reducing dust emissions in a metal or slag casting apparatus, as well as a metal or slag casting apparatus allowing reducing dust emissions, comprising an endless conveyor having a plurality of casting moulds with upper open tops and which endless conveyor is arranged to move said casting moulds in a first section from a casting station to a discharge station and in a second section back to the casting station, the method comprising (a) providing a casing forming a bottomless box over at least part of the first section of the endless conveyor, (b) injecting within said casing a gas on the surface of the mould with an angle sufficient to blow off loose, solid particles, such as graphite flakes, formed at the surface of the metal, during early stages of the cooling down and to start the solidification of a superficial layer of metal or slag, (c) extracting the gas and the solid particles by suction from within said casing.