Lightweight Alkali-Activated Material from Mining and Glass Waste by Chemical and Physical Foaming

Abstract

A foamed alkali-activated material (FAAM) based on tungsten mining waste (TMW) and municipal waste glass (WG) is fabricated by using aluminum powder and organic surfactant foaming agents. The compressive strength and density of the FAAM are investigated in terms of different parameters of production and formulation, including curing temperature as well as the dosage of Na2O, foaming agent, foam catalyzing agent, and stabilizing agent. FAAM made with aluminum powder consists of smaller open macropores and exhibits higher compressive strength compared with FAAMs with larger closed macropores obtained by organic surfactant counterparts. The final aluminum powder–based FAAM reaches a 7-day compressive strength in excess of 3 MPa and a density below 0.7 g/cm3. The implementation of an appropriate amount of foam stabilizer leads to a further 15% increase in compressive strength, 6% reduction in density, and a thermal conductivity below 0.1 W/mK. The FAAM explored in this study represents an ideal material for building envelope insulation.