Work

Optimization and Mechanistic Investigation of Coal Gangue–Blast Furnace Slag Composite Geopolymers

Year: 2025

Type: article

Abstract: Coal gangue (CG), a major solid waste generated during coal development, presents critical environmental challenges due to its large-scale accumulation and associated ecological impacts, thereby necessitating the development of efficient utilization strategies. This investigation developed a composite geopolymer system through the alkali-activated co-utilization of uncalcined CG and blast furnace slag (BFS), demonstrating an environmentally sustainable approach for industrial byproduct value addition. The effects of key parameters, including BFS content, liquid-to-solid ratio, alkali activator dosage, waterglass modulus, and curing regime, on the strength development were first investigated through single-factor experiments. Based on these results, response surface methodology was applied to optimize the preparation parameters and develop a quadratic regression model describing the relationship between compressive strength and the influencing factors. The optimal conditions (a waterglass modulus of 1.06, an alkali activator dosage of 13.81%, and an initial 24 h curing temperature of 30 °C) were determined to maximize compressive strength. The reaction mechanisms were further explored using XRD and SEM-EDS, which confirmed the existence of calcium silicate hydrate, calcium aluminum silicate hydrate, and geopolymer gel in the composite geopolymer matrix.

Source: Processes

DOI: 10.3390/pr13061703

Authors: Shujie Zhao, Tian Ma, Dongwei Li, Ming Xia

Institutions: Anhui University of Science and Technology, Chongqing University, Jiangsu Ocean University

Language: English

Topic: Concrete and Cement Materials Research

Subfield: Civil and Structural Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Responsible consumption and production, Industry, innovation and infrastructure

Open Access status: gold

Estimated APC paid: $2,896