ABSTRACT
The coal-to-liquid gasification ash and slag (GAS) is a solid waste with high yield, difficult degradation and environmental hazards. In this study, a novel extinguishing grouting material was made in the light of GAS, and carboxymethyl cellulose (CMC) was introduced as a dispersant for GAS slurry for easy blockage and bursting of pipes during the transportation of grouting material. Zeta-potential measurement, X-ray fluorescence and water separation experiment were utilized to discuss the mechanism and suspension stability of GAS slurry with different water-cement ratios and amount of CMC addition. The fire extinguishing material and the optimal mixing ratios were also obtained. The content of SiO2, Fe2O3, CaO and Al2O3 in GAS accounted for more than 80% of the total composition, and the main substances were gypsum, quartz and calcite. CMC had a prominent improvement effect on the suspension stability of slurry, and the more the added dosage, the stronger the suspension stability. The slurry suspension stability was maintained by steric hindrance and electrostatic repulsion; when the water-cement ratios were 1: 0.8, 1: 1.0 and 1:1.4, the optimal addition amounts of CMC were 1.5%, 1.25% and 0.75%, respectively.
Acknowledgements
This work was supported by the National Natural Science Foundation of China (Grant numbers [51974236]), Natural Science Basic Research Program of Shaanxi Province (Grant numbers [2021JC-48]), and Central Government for Local Science and Development of Shaanxi Province (Grant numbers [bcby-2020-02]). The authors also acknowledge the Key Laboratory of Coal Fire and Hazard Prevention in Shaanxi Province, China.
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No potential conflict of interest was reported by the author(s).
Additional information
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Notes on contributors
Xiaowei Zhai
Xiaowei Zhai Ideas and experimental protocols, Supervision, Review, Funding acquisition.
Yujie Zhou
Yujie Zhou Writing- review & editing, Experiments, Analysis, Revises.
Duo Zhang
Duo Zhang Methodology, Review.
Bobo Song
Bobo Song Experiments, Review.
Le Hao
Le Hao Analysis, Review.