Chemical durability of a slag glass from pig iron production: reaction products, surface alteration and kinetics

摘要

Glassy slags are byproducts of pyrometallurgical processes and are used as latent hydraulic binders or as an additive in ordinary Portland cement in the production of blast furnace cements. The reactivity of the ground slag glasses is usually lower than the reactivity of the binding phases in ordinary Portland cement. Their reactivity can be enhanced by adding either basic compounds or calcium sulphate compounds. The dissolution of the slag glasses is essential for the formation of their binding phases. The slag tested here was a calcium/magnesium aluminosilicate glass. The glasses were tested either as ground original materials or, in other tests, as remelted bulk glasses. The glasses were corrosion tested for times up to 84 d in H2O or solutions containing CaSO4 or Ca(OH)(2) at 50 degrees C. After the corrosion process an altered layer was found on the glass surface. The leachate was chemically analyzed. The altered glass surface was analyzed by scanning electron microscopy (with elemental analysis) and x-ray diffraction.