In the heart of China’s coal mining regions, a groundbreaking study led by Jiaxu Jin from the School of Civil Engineering at Liaoning Technical University is paving the way for more sustainable and efficient mining practices. Jin and his team have been tackling one of the industry’s most pressing challenges: what to do with the massive amounts of coal gangue, a solid waste product of coal mining that has long been a thorn in the side of miners and environmentalists alike.
Coal gangue, with its significant quality fluctuations, high crushing value, and poor stability, has been a technical bottleneck in the quest for resource utilization in coal mines. But Jin’s research, published in the journal ‘Meitan kexue jishu’ (which translates to ‘Coal Science and Technology’), is changing the game. The journal is a staple in the industry, known for its rigorous peer-review process and high-impact publications.
The team’s innovative approach involves surface-strengthening treatments for low-grade coal gangue using slurry-wrapping and powder-wrapping methods. They then used the modified coal gangue to prepare pre-placed coal gangue cemented backfill (PCCB), a promising solution for goaf backfilling—the process of filling empty spaces in mines with waste material.
Jin explains, “Our study showed that both treatment processes significantly reduce the crushing value of coal gangue, thereby improving the mechanical properties of PCCB.” This is a big deal for the energy sector, as it opens up new possibilities for the large-scale application of backfilling in goafs, ultimately leading to more sustainable mining practices.
The research team employed digital image correlation technology and acoustic emission technology to study the effects of surface strengthening treatment of coal gangue on mechanical properties and uniaxial compression damage behavior of PCCB. Their findings revealed that the uniaxial compression failure mode of the PCCB specimen is mainly tensile failure. Moreover, after the surface strengthening treatment of coal gangue, the crack initial rate and crack damage rate of PCCB are significantly improved, enabling it to better resist crack growth during the compression damage process.
Jin’s work is not just about improving the mechanical properties of PCCB. It’s also about understanding the underlying mechanisms. The study found that when the coal gangue aggregate is treated by the slurry-wrapping method, the main influencing factor of the strength of PCCB is the crushing value of the modified coal gangue aggregate. However, after the powder-wrapping method, the modified aggregate and the aggregate-matrix interface transition zone affect the strength of PCCB.
This research is a significant step forward in the quest for green mine construction and resource recycling. It provides theoretical support and practical guidance for the application of PCCB in goaf backfilling, potentially revolutionizing the way the energy sector handles solid waste.
As the world grapples with the challenges of climate change and sustainability, Jin’s work offers a glimmer of hope. It’s a testament to the power of innovation and the potential of technology to drive positive change in the energy sector. The study not only opens up new avenues for the utilization of coal gangue but also sets a precedent for the responsible management of solid waste in mining operations.
In the words of Jin, “Our research opens up a new way for green mine construction and resource recycling.” And with the energy sector under increasing pressure to adopt more sustainable practices, this research couldn’t have come at a better time. It’s a reminder that even in the most challenging of industries, innovation and sustainability can go hand in hand.