An experimental and theoretical study is performed on a gas-particle stirred ladle system with throughflow of molten metal, using a simplified water model.  The ladle is a slender rectangular tank with a two-dimensional flow field.  An air stream (simulating the carrier gas) mixed with neutrally buoyant solid particles (simulating desulphurization agent) is injected through a nozzle into the ladle, thus forming a jet to stir the throughflow of water (referred to as injection metallurgy).  The flow pattern in a ladle, gas-particle-liquid mixing characteristics (i.e. the mixing time and the jet trajectory and the penetration length of a gas-particle mixing jet from an injection nozzle), and the bubble and particle behavior at the outlet of an air-particle injection nozzle are investigated using direct photographic method, image processing, laser speckle photographic method, and particle image velocimetry.  The flow characteristics in the ladle are analyzed by means of turbulence models.