煤矿安全2025，Vol.56Issue(11)：1-8,8.DOI:10.13347/j.cnki.mkaq.20240774
粒径与浸水程度对煤孔隙结构的差异化影响
Differential impact of sample size and water immersion degree on coal pore structure
摘要
Abstract
To investigate the differences in pore structure with different particle sizes when coal body immersed in different amounts of water,coal samples with three particle sizes and four degrees of immersion were prepared using fat-coal(FM)and coking coal(JM).The low-temperature nitrogen adsorption experiment was conducted to determine the pore structure of coal,and fractal theory was employed to accurately quantify the pore structure.The study analyzed the differential effects of water immersion degree and particle size on coal pore structure.The research results show that under the same degree of immersion,as the particle size decreases,the specific surface area,single-layer saturated adsorption capacity,total pore volume,and isothermal adsorption capacity of the coal sample all show an increasing trend,and the change in specific surface area is the most obvious.The BET specific surface area of coal samples with particle size of 0.15-0.18 mm is about three times that of coal samples with particle size of 0.25-0.85 mm.The single-layer saturated adsorption capacity is positively correlated with the change in specific surface area,and the growth of JM is particularly significant at the minimum particle size.The analysis of total pore volume shows that the pores are mainly mesopores,and after water immersion,some coal samples exhibit the phenomenon of large pore collapse and an increase in mesopores,resulting in a decrease followed by an increase in pore volume.The isothermal adsorption curve shows that the adsorption process conforms to the typical characteristics of mesoporous materials,and the adsorption capacity of coal samples with the smallest particle size(0.15-0.18 mm)is always the highest.The effect of immersion has a dual nature:at low immersion rates,water occupies large pores,lead-ing to structural collapse and a decrease in specific surface area and single-layer saturated adsorption capacity;when the immersion water is high,the dissolution effect promotes the secondary development of pores,and the relevant parameters increase accordingly.The fractal characteristics further indicate that the fractal dimension changes of coal samples after water immersion do not follow a single law,but are jointly regulated by the degree of immersion and particle size.The degree of immersion and sample size are key factors leading to differentiated changes in coal pore structure.关键词
水浸煤/孔隙结构/低温氮气吸附法/比表面积/分形维数Key words
water-immersed coal/pore structure/low temperature nitrogen adsorption method/specific surface area/fractal dimen-sion分类
矿山工程引用本文复制引用
董宪伟,刘雨鑫,王福生,董轩萌,谢晓啸,李晓茜..粒径与浸水程度对煤孔隙结构的差异化影响[J].煤矿安全,2025,56(11):1-8,8.基金项目
国家重点研发计划资助项目(2023YFC3009105) （2023YFC3009105）
国家自然科学基金资助项目(51974128) （51974128）
