Tungsten mine waste geopolymeric binder: preliminary hydration products investigations

Abstract

Geopolymeric mine waste mud (GMWM) binders are obtained from dehydroxylated waste powder mixed with minor quantities of calcium hydroxide, activated with NaOH and waterglass solutions. In this work recent investigations of GMWM binders hydration products have been carried out. The hydration products have been investigated by means of X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS). Results indicate that mechanical strength as a function of the concentration of the alkaline activator is closely related to the mineralogy of the hardened geopolymeric binder. Results show that a new crystalline phase, phlogopite a trioctahedral layered structure, was formed as a result of the geopolymerization process. SEM and EDS analysis indicates that the hydration products were alkali aluminosilicate gel and calcium silicate hydrates.