Abstract: A process of refining steel in a ladle using solid granules or briquettes made from recycled LMF slag and raw materials to make a desulfurizing addition, a slag conditioner or synthetic refining slag is described. The preferred recycled LMF slag material generally comprises of 35% to about 65% CaO; 10% to about 35% Al.sub.2 O.sub.3 ; 1% to about 10% SiO.sub.2 ; 3% to about 15% MgO; 0.3% to about 10% FeO; 0.1% to about 5% MnO; 0% to about 0.5% P.sub.2 O.sub.5 ; and 0.1% to about 0.5% S. The ladle refining additive comprises from about 10% to about 90% of a recycled ladle metallurgy furnace slag and the balance of raw materials selected from the group consisting of: a calcium oxide source; soda ash; fluorspar; borax; calcium carbonate; aluminum source; calcium aluminate; alumina source; metallic calcium, magnesium, sodium and their oxides, fluorides and carbides; and mixtures of all of the foregoing.