Shao Xiaoping, Xu Baowa, Tang Renlong, Liu Lang, Fang Zhiyu, Tian Chuang, Ning Jianbo, Li Longqing
Energy School, Xi'an University of Science and Technology, Xi'an, 710054, China.
Key Laboratory of Western Mines and Hazards Prevention, Ministry of Education of China, Xi'an, 710054, China.
Environ Sci Pollut Res Int. 2023 Mar;30(15):45015-45028. doi: 10.1007/s11356-023-25382-1. Epub 2023 Jan 26.
To promote the widespread use of fly ash (FA) and coal gasification slag (CGS) in mine filling, reducing the amount of cement and promoting the sustainable development of mining enterprises are essential. In this study, decarbonized CGS (DCGS) was prepared from CGS through decarbonization. A new DCGS-FA filling material was prepared using DCGS, FA, cement (3 wt.%), sodium sulfate (SS), and aeolian sand (AS). The effects of different mass ratios (1/9-5/5) of DCGS/FA on the properties of new filling materials were investigated. The results indicate that CGS can be used with FA to prepare filling materials after decarbonization. The flow performance of the DCGS-FA filling material is positively correlated with the mass ratio of DCGS/FA, while the mechanical properties are negatively correlated. The 28-day unconfined uniaxial compressive strength (UCS) of all specimens met the mechanical requirements (UCS ≥ 1.0 MPa). The types of hydration products were determined through X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. The main hydration products of DCGS-FA filling materials are ettringite (AFt) and C-S-H gel. The results of the TG/DTG test of 28 days revealed that an increase in the DCGS/FA mass ratio would reduce the content of hydration products in filling materials. When the mass ratio increased from 1/9 to 5/5, the content of hydration products in the filling material decreased by 54.5%. This study provides a new concept for the resource utilization of CGS and FA in mine filling, which can significantly reduce the amount of cement in filling materials and promote the sustainable development of mine filling.
为促进粉煤灰（FA）和煤气化炉渣（CGS）在矿山充填中的广泛应用，减少水泥用量并推动矿山企业可持续发展至关重要。本研究通过脱碳由CGS制备了脱碳CGS（DCGS）。采用DCGS、FA、水泥（3 wt.%）、硫酸钠（SS）和风积砂（AS）制备了一种新型DCGS-FA充填材料。研究了不同质量比（1/9 - 5/5）的DCGS/FA对新型充填材料性能的影响。结果表明，CGS经脱碳后可与FA用于制备充填材料。DCGS-FA充填材料的流动性能与DCGS/FA的质量比呈正相关，而力学性能呈负相关。所有试样的28天无侧限单轴抗压强度（UCS）均满足力学要求（UCS≥1.0 MPa）。通过X射线衍射、扫描电子显微镜和能谱分析确定了水化产物类型。DCGS-FA充填材料的主要水化产物是钙矾石（AFt）和C-S-H凝胶。28天的TG/DTG试验结果表明，DCGS/FA质量比增加会降低充填材料中水化产物的含量。当质量比从1/9增加到5/5时，充填材料中水化产物的含量下降了54.5%。本研究为CGS和FA在矿山充填中的资源利用提供了新思路，可显著减少充填材料中的水泥用量，促进矿山充填的可持续发展。
