Method for agglomerating steel plant waste dusts

摘要

Highly crush-resistant hardened agglomerates are produced from steel plant waste dusts by forming a moistened mixture including (a) one or more of such dusts, (b) about 2 to about 20 weight percent of a bonding agent, such as lime or calcium hydroxide, and (c) about 0.5 to about 5 weight percent of a siliceous material, such as silica; aging the moistened mixture at an elevated temperature for a sufficient time to hydrate the overburned lime and/or slag contained therein; forming the aged mixture in discrete, green agglomerates; adjusting the moisture content of the green agglomerates to about 5 weight percent or less; and then hydrothermally hardening the green agglomerates to a hardened form. The crushing or compressive strength of the hardened agglomerates can be further increased by subjecting them to a drying step to remove at least a portion of the moisture contained therein immediately after the hydrothermal hardening step.