Characterisation of LD slag of Bokaro Steel Plant and its feasibility study of manufacturing commercial 'fly ash–LD slag' bricks
The aim of this study is to couple several analytical techniques in order to carefully undertake physical, chemical and mineralogical characterisations of LD steel slag to determine its feasible utilisation in commercial brick manufacturing. The characterisation results of LD slag showed that the pH and electrical conductivity of the samples were very high indicating high percentage of lime presence and presence of ionic form of various salts, respectively. The specific gravity and bulk density of LD slag samples were found to be high in comparison to fly ash samples. The EDS X–ray micro analysis showed that major elemental compositions of LD slag samples are O and Ca by weight. The XRF analysis showed that the major components of the LD slag samples are CaO, FeO and SiO2. The differential thermal analysis result showed that an endothermic peak at 450.7°C in the DTA curve was found. The compressive strength of the brick samples type A (Fly ash - 35% + LD slag - 30% + Gypsum - 5% + Quarry dust - 20% + Lime - 9.75% + CaCl2 - 0.25%) was found to be more than 100 kg/cm2 after 14 days of curing which is sufficiently higher than that of the strength of a normal red clay bricks (50-70 kg/cm2) and may be its feasible replacement for commercial purposes in civil jobs.
Keywords: LD slag, brick, fly ash, waste management, characterisation