The present invention relates to a process and to a
system for eliminating the expandability of steel-
plant slag, which comprises a primary
crusher (3) to reduce the fragments according to their granulometry; a
magnetic separator (4) to remove metallic fragments bigger than a determined granulometry (5); a rotary dryer (6) to dry
slag free from bigger metallic fragments; an
impact mill (11) to disaggregate and fragment
slag particles that are bigger than a predetermined granulometry; a classifier (12) for aero-classification and drag of fine and superfine particles; a cooler (17) for cooling slag particles bigger than a predetermined granulometry by means of heat exchange and removal of the fine and superfine particles that were not collected by the
impact mill (11); a vibrating
sieve (21) provided with two or more decks (23, 24, and 25) with screens of predetermined sizes; low-intensity magnetic separators (26, 27 and 28), with generation of non-magnetic slag fractions free from metallic iron and from iron
monoxide, and of magnetic fractions composed by metallic iron and iron
monoxide; and low-intensity magnetic separators (35, 36 and 37) to reprocess the magnetic fractions with generation of concentrate with high metallic iron contents and a product with
high concentration of iron
monoxide.