Producing a device for retaining slag in the converter is consider in this study, A device forseparation of slag and its retention in a tapping converter which consists as a closure. The device has a density higher than slag and lower than the steel. It submerges between the slag and steelthat called Slag dart.slag dart consist of tail and head, head has a higher density than tail. The tail goes in to the tap hole and the head approaches the hole until closing it. It was studied to produce the dart from two castables with Bauxite and high Alumina. Calcium aluminates cement was used as a binder. Bauxite base castable had Mullite phases inside the poresrespectively. The factor n=0.22 in Anderiasen Equation and 8 wt% cement had a strength higher than high alumina base castable. The effect of 20 wt% of 5 and 1 mm steel balls on physical and mechanical properties showed that smaller size provides better distribution and higher strength. 1 mm size steel balls also produce less expansion cracks and better corrosion resistance. The density of castable in tail was increased from 2.4 to 3.6 g/cc in head.2wt% steel fibers of 0.5 cm diameter increases the compressive strength from 45 to 52 MPa. Keywords: Slag dart, Slag, Clean steel, Converter,Castable high alumina
