An infrared spectroscopic study of non-metallic portion of Linz-Donawitz slag fines generated at Tata Steel, Jamshedpur

Abstract

The main constituents of LD Slag fines in the size range of 0–6 mm after recovering the metallic iron in a waste recycling plant (WRP) mainly contains calcium bearing mineral phases such as mono, di and tricalcium silicates along with free lime. The chemical constituents are CaO, SiO2, FeO and Al2O3 with traces of chromium, manganese, etc., as oxides. The WRP waste, i.e., LD Slag fines of 0–6 mm is further subjected to sieving mainly into three different size fractions viz. + 10 mesh (−6.0 + 2.0 mm), + 60 mesh (−2.0 + 0.25 mm), −60 mesh (−0.25 mm) for studying its possible application economically in different sectors such as agriculture, construction and chemical industries. Chemical and XRD analysis indicate high lime content along with some compounds like calcite, silicates of calcium, brownmillerite and dicalcium diferrate, etc., in these slag samples. FTIR analysis of these size fractions also indicates the presence of hydrated silicates, calcite and anhydrous calcium silicate. In this study, the authors have attempted to correlate the chemical analysis and XRD studies with FTIR technique of characterisation for better understanding of the parent material. This was done to get a deeper insight of the fines which can be useful for development of suitable calcium-based value added materials for different industrial, chemical and agricultural applications.