Agglomeration of steel plant waste dusts - by hydrothermal treatment of an aged wet mixt of dust, bonding agent and silica

摘要

Hard agglomerates are made from steel plant waste dust contg. a hydrateable matl. of overburned lime and/or slag matl. by (a) forming a moist mixt. of the waste dust, 2-20 wt % (dry wt.) Ca and/or Mg (hydr)oxides and carbonates and 0.5-5 wt % Si matl. capable of forming a silicate bond with the bonding agent, the solids being 10 mesh size (b) ageing the mixt. to hydrate the hydrateable matl (c) forming into discrete masses (d) drying to 5 wt % moisture, and (e) hydrothermally hardening by contact with satd. steam at 100-244 degrees C. Compressive strength can be enhanced by drying after hydrothermal hardening to remove at least part of the moisture. Prod. may be used as a steel making process charge.