Mechanical and Environmental Properties of Cemented Paste Backfill Prepared with Bayer Red Mud as an Alkali-Activator Substitute.

ABSTRACT: This study developed a sustainable high-strength coal gangue backfill material for underground mining applications using coal gangue, fly ash, and cement as primary raw materials, with red mud (RM) as an alternative alkali activator. The mechanical properties of the backfill material were systematically optimized by adjusting coal gangue particle size and alkali activator dosage. The optimized formulation (coal gangue/fly ash/cement = 5:4:1, 3-6 mm coal gangue particle size, 5% RM, which named BF-6-5RM) achieved superior compressive strengths of 8.23 MPa (7 days) and 10.5 MPa (28 days), significantly exceeding conventional backfill requirements and outperforming a CaO-activated reference system (coal gangue/fly ash/cement = 5:4:1, 3-6 mm coal gangue particle size, 2% CaO, which named BF-6-

SUBMITTER: Gao L 

PROVIDER: S-EPMC12566605 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature