Development of Cleaner One-part geopolymer from lithium slag

Abstract

In this study, lithium slag waste was utilized for the development of eco-friendly ambient cured one-part geopolymer. Lithium slag and blast furnace slag were employed as alumino-silicate precursors and anhydrous sodium silicate as alkaline activator. Fresh properties were assessed using setting time and flowability tests, while compressive strength, flexure strength, water absorption and drying shrinkage tests were performed to evaluate hardened properties of newly developed geopolymer mix. X-ray Diffraction analysis (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy examination (SEM) were performed to evaluate the chemical functional groups and microstructure of the mix. The environmental impact analysis was determined through measurement of carbon dioxide equivalent (CO2-e) of constituents. The experimental investigation revealed that blast furnace slag addition in lithium slag based geopolymers improved its reactivity and hardening was achieved at room temperature. The 57 MPa compressive strength was achieved, which is comparable with other one-part geopolymers prepared using similar precursors. The improvement in mechanical strength can be attributed to enhanced geopolymerization reaction and improvement in gel structure as observed through microstructural testing.