Main objective of this study is to recycle shell wastes from the investment casting industry, using powder technology to produce refractory parts. Refractory powders were recovered from bulk wastes using a ball-milling technique and injection-moulded to produce refractory parts. Many thousands of complex-shaped parts were injection-moulded by optimising the process parameters. Recycled powders and the parts were characterized by particle size analysis, scanning electron microscopy, thermogravimetric analysis, density, and size measurements. Performance of the injection-moulded products was tested in sampling operations at molten steel under industrial steelmaking practice. The results allow us to conclude that the shell wastes can be effectively milled and used to produce refractory parts by the injection moulding process. After injection moulding followed by sintering, the final products present a porous microstructure, which has a beneficial effect on their thermal shock resistance.