Manganese is an important alloy addition for alloy steels. It is normally added to steel melts as ferromanganese. However, for the adjustment of melt composition, manganese metal is used as a trimming addition since it has lower levels of impurities than ferromanganese. The manganese used for this purpose is obtained from the electrolytic processing route wherein selenium-containing additives are added to the electrolyte bath to improve the current efficiency. This practice introduces selenium to the manganese metal. Given that selenium and its compounds are potentially toxic and damaging to the work place and environment, effluents have to be treated in a controlled manner. In order to determine how selenium typically distributes between molten steel, slag and gas phases, a laboratory-scale experimental study was carried out to evaluate the deportment of selenium following the addition of selenium containing manganese to the steel melt. Contaminated commercial manganese metal, as well as Mn-AI-Se spiked briquettes with different selenium contents were added to steel melts at 1600 "O. Selenium recovery to the solidified steel samples varied from 16% to 75%, depending on selenium levels of additions. Owing to the high vapour pressure of selenium, significant amounts of the selenium added to the melt evaporated, reacting with air to form selenium dioxide. SEM analysis of the solidified steel samples revealed that the selenium was largely present as manganese selenide (MnSe) in the form of spherical inclusions within the iron matrix. A thermodynamic assessment on the potential formation of possible selenium compounds within the steel melt suggests that the most stable selenium compound under the test conditions is MnSe, in accord with experiments.