Synthesis and characterization of yellow gypsum from LD slag fines generated in a steel plant

We describe here a simple method for synthesis of a value-added product (yellow gypsum) from Linz–Donawitz slag (LD slag), which is an industrial waste product of the steel industry. XRD analysis of the product confirmed the presence of anhydrite and gypsum phases as well as the presence of iron, silica and titanium in the form of fayalite and illmenite phases. A weight loss of 17.26% was observed from the TG analysis, indicating the presence of mixture of the dihydrate, hemihydrate, soluble γ-anhydrite and insoluble β-anhydrite phases of gypsum in the product.