Geopolymer concrete, a sustainable substitute for Ordinary Portland Cement (OPC), has traditionally relied on commercial alkali activators like sodium hydroxide and sodium silicate, which are costly and environmentally detrimental. This study investigates the technical feasibility of using desulfurization dust (DeS-dust) from the steel industry and sodium silicate extracted from rice husk ash (RHA-SS) as sustainable replacements for commercial activators in Fly Ash-Ground Granulated Blast Furnace Slag (FA-GGBS)-based geopolymer concrete. These alternative activators aim to mitigate the environmental footprint and costs associated with commercial activators. The viability of using industrial wastes such as DeS-dust and RHA-SS was confirmed through pH, FTIR, EDAX and acid titration analyses. The DRG100 mix, comprising 60% FA and 40% GGBS as precursors activated with RHA-extracted sodium silicate solution and DeS-dust, demonstrated remarkable improvements in mechanical and durability properties. This mix completely replaced commercial activators with waste-sourced alternative activators. The compressive strength of DRG100 reached 48.24 MPa, a 27.23% increase compared to the control sample with traditional activators (37.9 MPa). Durability was enhanced, with water absorption reduced by 13.3% and chloride ion permeability decreased by 57.1%. Thermal stability tests revealed that DRG100 retained 86.2% of its weight and maintained a residual compressive strength of 24.2 MPa at 900°C. Additionally, production costs were reduced by 67.9%, highlighting economic and environmental benefits. © 2025 Elsevier B.V., All rights reserved.