Silicon reduced Argon Oxygen Decarburization slag (Si-AOD) is a common by-product from manufacturing of stainless steel. In this work the possibility to use the slag as adsorbent for some selected metals (Cr, Ni, Cu, Zn and Pb) is tested. The slag was obtained from Outokumpu, Avesta, Sweden as one black, powder like, and one greenish, pumice-stone like. Due to its small grain size the black Si-AOD was not suitable as a filter material since it quickly clogged and formed almost impermeable layers. However, the greenish Si-AOD with its porous structure showed good permeability and seems to be good as a filter material. Its ability to remove the selected elements from an aqueous solution was tested at different metal concentrations, ionic strengths and pH. The absorption capacity was tested in columns each holding 30 gram of the greenish Si-AOD and 300 mL of the aqueous phase was passed through the material. Six fractions of 50 mL each were collected and analyzed with respect to pH and metal content to estimate the retention capacity. With an initial concentration of 10 mg/L (Ni, Cu and Zn) and 1 mg/L (Cr and Pb) an almost 100% adsorption was obtained. The adsorption seemed to follow the Freundlich adsorption isotherm and with a 1/n-value of 0.13 the adsorption process is probably chemical. The adsorption capacity of the surface was estimated to be at least 80 μeqv/g. Hence a liquid to solid ratio of up to 100 can be reached with the used metal solution before the retention capacity of the slag is depleted