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Preliminary Study of Preheated Decarburized Activated Coal Gangue-Based Cemented Paste Backfill Material
Renlong Tang1,2, Bingchao Zhao1,2, Chuang Tian1
1Energy School, Xi'an University of Science and Technology, Xi'an 710054, China.
Materials (Basel, Switzerland)
|March 29, 2023
Summary
This study introduces a novel coal gangue-based cemented paste backfill material for green mining. The material effectively utilizes coal gangue waste, meeting strength requirements and stabilizing heavy metals.
Area of Science:
- Materials Science
- Environmental Engineering
- Mining Engineering
Background:
- Coal gangue (CG) is a significant solid waste from coal mining.
- Effective utilization of CG is crucial for sustainable mining practices.
- Developing eco-friendly backfill materials is essential for green mining.
Purpose of the Study:
- To propose and evaluate a novel coal gangue-based cemented paste backfill material (PCCPB) for green mining.
- To investigate the impact of sodium sulfate (Na2SO4) on PCCPB performance.
- To assess the environmental safety and microstructural characteristics of PCCPB.
Main Methods:
- Preparation of PCCPB using preheated decarburized coal gangue (PCG), fly ash (FA), activator, cement, and water.
- Decarbonization and activation of CG via preheated combustion at 900 °C for 4 min.
- Comprehensive testing including mechanical, microscopic, and leaching toxicity analyses.
Main Results:
- PCCPB with optimal Na2SO4 dosage (3%) met backfill mining strength requirements (e.g., 4.312 MPa at 28 days).
- Leachate analysis confirmed heavy metal ions met groundwater standards, indicating stabilization.
- Microstructural analysis (FTIR, TG/DTG, XRD, SEM) elucidated material formation and stabilization mechanisms.
Conclusions:
- PCCPB offers a viable solution for large-scale coal gangue utilization and resource recovery.
- The developed material contributes to green mining by reducing solid waste and stabilizing heavy metals.
- This research promotes sustainable coal gangue activation and consumption.
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