A recent study highlights the creation of briquettes aimed at improving safety measures within coal mines, particularly concerning gas disaster prevention. This innovative research, published on March 11, 2025, details the impact of varying heating temperatures on the pore structure of briquette coal (BC), which could potentially replace traditional raw coal (RC) samples used for physical simulation experiments.
Coal remains one of the primary energy resources, especially within China, where extensive reliance on coal has prompted the need for safer mining solutions. Deep coal mining operations exceed depths of one kilometer, posing significant risks, exemplified by the alarming rise of coal and gas outburst fatalities from 3.4% to 13.5% of total mining deaths between 2001 and 2021. This has escalated safety measures at the national level, making research on effective simulation materials for disaster prevention increasingly urgent.
The academic team responsible for the study used advanced techniques involving scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), low-temperature liquid nitrogen adsorption tests (LTNAT), and CH4 adsorption-desorption tests to evaluate how pore structures change at different temperatures during briquette formation. They found compelling evidence linking increased heating temperatures to changes in pore sizes, enhancing the briquette's effectiveness in simulating raw coal samples.
A key focal point of the study reveals how temperature adjustments during briquette preparation affect pore characteristics. For example, SEM analysis illustrated increased surface roughness and significant pore development at temperatures above 300 °C. This progressive change indicates how heating facilitates the transition of micropores to larger macropores, which is significant for coal's permeability and structural integrity.
NMR analysis corroborated these findings, showing the diminishing presence of micropores as heating temperatures rise above 300 °C, which correlates directly with increased macropore formation. These observations are pivotal for improving the reliability of briquette coal used for simulating raw coal behavior during physical experimentation.
At 300 °C, it was determined through analyses from both SEM and NMR measurements, the total porosity of briquette coal was inferior to other coal samples. Contrarily, CH4 adsorption-desorption tests indicated heightened adsorption capacities when briquette temperature thresholds were elevated during preparation. The researchers concluded utilizing the Langmuir model effectively represented the adsorption behaviors, noting the constants ‘a’ and ‘b’ changing with increased brquette heating temperatures. Specifically, 'a' increased and 'b' decreased, highlighting improved methane adsorption characteristics.
With clear insights established from the low-temperature nitrogen test and the derivation of the inverted “S” type and IV type isothermal adsorption curves observed during testing, the study aptly asserts how preparing briquettes at higher temperatures yields advantages for coalbed methane application. Notably, the minimization of peak values for pore volume and specific surface area was observed at 600 °C, marking it as significant for future briquette production.
Overall, the research contributes to advancing safe mining practices, emphasizing the ability to engineer materials with specific properties aligned with operational requirements. Enhancing briquette coal’s characteristics through controlled heating provides invaluable data for safety protocols aimed at mitigating gas outbursts during coal extraction. The findings not only aid future production but also reinforce the importance of thorough analyses when developing practical solutions to contemporary challenges within the coal mining sector.
By addressing how temperature influences the physical and chemical behavior of briquette coal, this study outlines necessary pathways for future research, paving the way for safer and more viable extraction methods across increasingly complex geological environments. Strengthening the link between empirical research and practical application could lay the groundwork for improving coal mining safety as industry standards evolve to meet the growing demands for sustainable and responsible energy production.