Processing of steel making slag

A system for processing slag material from a steelmaking process includes reducing the average particle size of slag from a steelmaking process into finer particle size material by directing the slag against a surface at a velocity sufficient to cause the slag to break into smaller pieces, and separating the finer particle size material into at least an iron rich product and a silicate rich product based on the differences between these products in at least one or more properties including magnetic susceptibility, particle size, weight or specific gravity. Directing the slag against a surface to reduce the average slag particle size can better separate the dissimilar materials in the slag from each other, and result in less dust generation and less energy consumption compared to grinding the slag material.