“Implementing regional advanced gas control means scientifically planning and taking proactive measures to effectively manage coal seam gas in advance, transforming outburst-prone seams into non-outburst-risk seams before mining, thereby avoiding a direct ‘hand-to-hand fight’ with gas,” stated a representative from the National Mine Safety Administration during the National Coal Mine Gas Control Site Promotion Conference held on March 20-21.

The conference emphasized the need to further strengthen the concept of safe development, implement the “20-character” gas control system of “reliable ventilation, qualified extraction, precise outburst prevention, effective monitoring, and thorough management,” and comprehensively enhance gas control capabilities and standards.

Significant Reduction in Gas Accidents and Fatalities

In recent years, China’s coal mine gas control efforts have achieved remarkable results, with a significant decline in the number of gas accidents and fatalities. From 2021 to the present, China experienced three major coal mine gas accidents, resulting in 38 fatalities. Compared to the high-incidence period from 2000 to 2006, the average annual number of accidents and fatalities decreased by 98.1% and 98.9%, respectively.

These achievements are attributable to the increasingly scientific approach to gas control, rapid technological upgrades in equipment, and the continuous improvement of the gas control system.

As the concept of gas control has deepened, coal mining enterprises have gained a more profound understanding of gas hazards, significantly strengthening their resolve and confidence in disaster prevention.

Huaibei Mining Group has adhered to the philosophy that “major disasters are subversive yet preventable and controllable,” maintaining a gas-accident-free record for 17 consecutive years. China National Coal Group has embraced the principle that “controlling gas liberates productivity, and effectively managing gas enhances productivity,” achieving zero outbursts for ten consecutive years. Sichuan Coal Industry Group has upheld the concepts that “gas must be prevented and controlled” and that “exceeding limits constitutes an accident,” reducing the number of gas exceedances to single digits for three consecutive years.

Technological and Equipment Advancements Driving Gas Control

Various regions and coal mining enterprises have prioritized technology and equipment as the primary drivers for improving gas control capabilities.

Protective seam mining technology has been fully implemented, while surface well extraction technology has been widely adopted. Guizhou has shifted from prioritizing thicker seams to developing protective seams. Coal mines in Anhui, Shanxi, Shaanxi, and other regions have commonly adopted surface well extraction technology to manage pressure-relief gas and goaf gas. Huaibei Mining Group has applied combined surface and underground extraction technology, constructing over 400 surface extraction wells since 2020, with a single well achieving a maximum gas extraction volume of 5 million cubic meters.

Meanwhile, underground drilling technology and permeability enhancement techniques for soft coal seams have steadily improved, with notable progress in borehole slotting and permeability enhancement. The Huainan-Huaibei region has adopted permeability enhancement methods, such as large-diameter slotting, for soft, low-permeability seams, increasing the slotting radius from 153 mm to 500 mm, significantly improving pressure relief and permeability enhancement.

The rapid upgrading of drilling equipment has provided a solid foundation for gas control. The drilling capacity of underground rigs has increased from low to high, enabling deeper and more precise drilling when combined with tools such as borehole attitude instruments. Directional drilling technology has advanced from nonexistence to widespread use, with domestically developed directional rigs achieving precise positioning. Surface drilling rigs are now widely utilized, enabling regional gas control to be implemented five to eight years in advance. Breakthroughs have also been made in the development of automated and intelligent drilling rigs. Linhuan Coal Mine of Huaibei Mining Group established the industry’s first intelligent drilling and extraction operation line, increasing per-capita work efficiency by 32% and reducing labor costs by 33.3%.

Upgrades to extraction systems, breakthroughs in rapid gas content measurement technology, and the successful application of rock tunnel boring machines have established a solid technological foundation for gas control.

Refined Management and Policy Support

Given the broad scope, specialized nature, and significant investment required for gas control, various regions and enterprises have adopted meticulous management approaches to comprehensively strengthen safety defenses.

The State Council launched the “two major battles” to close small coal mines and implement gas control, significantly eliminating small mines lacking gas control capabilities and optimizing the industrial structure. The implementation of the Opinions and the “Eight Hard Measures” has promoted a shift in gas control models toward “zonal management and advanced control.” Provinces such as Hebei, Shanxi, Anhui, Henan, Guizhou, and Shaanxi have introduced region-specific gas control measures. Guizhou, in particular, has strictly implemented its “eight measures” for coal mine gas control, formulating detailed implementation rules that have effectively curbed gas accidents. The province has now achieved 19 consecutive months without gas-related fatalities and 24 consecutive months without outburst-related injuries.

Local regulatory and supervisory departments have strengthened law enforcement in gas control, intensifying efforts to combat various fraudulent activities such as drilling, extraction, monitoring, and concealed working faces. In 2024, a total of 920 concealed working faces were identified nationwide, and 215 major accident hazards involving fraudulent activities were investigated.

Challenges Remain in Gas Control

Gas remains the “primary killer” in coal mine safety. Gas accidents can range from suffocation to severe explosions, resulting in varying degrees of casualties. The situation for coal mine gas control remains severe and complex, with a long road ahead.

A representative from the National Mine Safety Administration noted that significant challenges remain, including conceptual deviations, a mismatch between gas control capabilities and disaster severity, and technological bottlenecks that urgently need to be addressed.

Some enterprises have not genuinely embraced the concept that gas is preventable and controllable. When accidents occur, they often attribute them to “unforeseeable” factors and emphasize objective excuses. Others lack firm commitment, hesitating to invest in gas control measures, opting for short-term savings over long-term safety. Some enterprises fail to act decisively, frequently altering medium- and long-term gas control plans and annual implementation schedules to meet short-term production targets and operational goals.

The increasing severity of gas disasters demands higher standards for mine systems, equipment, technology, and management. However, some enterprises are ill-prepared, failing to adopt necessary gas control technologies and equipment, resulting in significant gaps in gas control capabilities.

“On-site management of gas control remains a prominent issue in some enterprises, which can be summarized by four words: falsification, concealment, roughness, and complacency,” said Zhou Dechang, Party Leadership Group Member and Deputy Director of the National Mine Safety Administration.

Zhou explained that “falsification” includes practices such as falsifying mine plans, concealing working faces, operating two sets of safety monitoring systems, tampering with sensors, and concealing underground personnel counts. In 2024 alone, provincial mine safety supervision departments investigated 367 cases of such fraudulent activities.

“Concealment” involves hiding exceedance alerts and accidents. Some enterprises conceal the true nature of accidents, attributing them to “stress” or “faults” while avoiding discussion of subjective responsibilities such as inadequate gas control, substandard extraction, and fraudulent outburst prevention.

“Roughness” refers to imprecise technical management, such as adopting boilerplate gas control plans without tailoring them to specific conditions. Some enterprises lack refined on-site management, failing to achieve precise extraction, resulting in low gas extraction concentrations and rapid decay. This leads to exceedances when mining faces collapse or roofs fall, and outbursts when encountering faults.

“Complacency” manifests in a lax mindset among some coal mining enterprises following prolonged periods of safety. Some enterprises become complacent after achieving “zero accidents” or “zero exceedances” for many years, leading to relaxed safety management.

On August 21, 2024, the Sihe Coal Mine in Leshan City, Sichuan Province, experienced a major gas explosion accident during the sealing of an air shaft, resulting in eight fatalities. The accident occurred due to the failure to inspect gas levels and the unauthorized use of open flames.

The National Mine Safety Administration representative also noted that the quality of some personnel needs improvement. Small and medium-sized coal mines, in particular, face a significant shortage of professionals specializing in gas control. Some safety management personnel lack basic professional competence, highlighting deficiencies in talent development.

Technological Breakthroughs Are Crucial

“Every advancement in gas control relies on technological innovation,” said the representative from the National Mine Safety Administration. “However, from the perspective of technological equipment support, significant bottlenecks remain to be overcome.”

Key challenges include the lack of substantive breakthroughs in the mechanisms of deep-seated gas disasters, the unresolved difficulty of extracting gas from soft, low-permeability, high-pressure coal seams, insufficient precision in gas early warning systems, and the significant gap between gas control and intelligent technologies.

For example, in soft, low-permeability, high-pressure coal seams, issues such as low drilling efficiency, difficulty in borehole formation, and susceptibility to blowouts persist. Existing drilling equipment, drilling techniques, and permeability enhancement measures have yet to fully address these challenges, requiring further technological breakthroughs.

Multi-Party Collaboration Enhances the Quality and Efficiency of Gas Control

In response to the current severe and complex situation of coal mine gas control, the National Mine Safety Administration has called for placing the management of major disasters such as gas in a more prominent position. Efforts should focus on strengthening the concept of safe development, implementing regional advanced control, enhancing precise outburst prevention, promoting advanced and mature experiences, strengthening technology R&D, reinforcing accountability, and improving the quality and efficiency of supervision and inspection, aiming to elevate coal mine gas control to a new level.

In the face of new circumstances and demands, various regions, regulatory and supervisory departments, and coal mining enterprises have collaborated and conducted a series of beneficial explorations and attempts to improve the quality and efficiency of gas control.

Shanxi has prioritized the transformation of gas control concepts as a breakthrough point to advance its work. Through symposia and exemplary guidance, coal mining enterprises are encouraged to consider the long-term and holistic picture. Lu’an Chemical Group adheres to the philosophy of “transforming thinking, implementing projects, and strengthening management,” striving for maximum extraction and using rock to protect coal. Huayang Group follows the principles of “comprehensive advancement, regional approach, and engineering orientation,” planning to invest 7.8 billion yuan in special funds for gas disaster control over five years.

Regional advanced control is a critical pathway for shifting gas management from reactive to proactive. Shanxi Coking Coal Group’s Shaqu No. 1 Coal Mine uses the No. 2 thin coal seam as a protective layer for the main mining No. 4 and No. 5 coal seams. During mining operations of the main coal seams, the return airflow gas concentration decreased by 28% to 60%.

“Precision” is key to the success of outburst prevention. Coal mining enterprises are intensifying efforts in parameter measurement, early warning, and response to achieve precision. Huaibei Mining Group has significantly improved the refinement of drilling and extraction. At Xutuan Coal Mine, the gas concentration in a single borehole reached up to 90%, and the net gas extraction volume per 100 boreholes reached 3 cubic meters per minute. All 60 coal and gas outburst mines in normal production and construction in Shanxi are equipped with underground one-stop rapid gas content detectors. Mine managers and chief engineers have shifted from “reviewing reports” above ground to “measuring data” underground.

The promotion and application of new technologies and equipment can yield multiplier effects in gas control. All high-gas and outburst mines under China National Coal Group have applied directional drilling rigs for regional gas control, achieving “borehole replacement of roadways” with 200 mm large-diameter directional boreholes under complex roof rock conditions. Huaibei Mining Group has introduced 11 mining tunnel boring machines, achieving breakthrough advancements in the construction of gas control roadways.

In terms of technology empowerment, the Binchang mining area in Shaanxi has strengthened research on “regional gas outburst prevention technology through staged fracturing of underground directional boreholes,” promoting a shift from single underground gas disaster control to integrated surface and underground management, as well as coordinated multi-disaster control in mines with coupled disaster zones. With the support of comprehensive gas control technologies, Henan Energy Group’s gas extraction and utilization volumes increased from 310 million cubic meters and 110 million cubic meters to 370 million cubic meters and 190 million cubic meters, respectively, from 2020 to 2024.

Regarding accountability, Sichuan Coal Industry Group adheres to daily risk assessments, identifying risks in key working faces and operational links, formulating control measures, and assigning responsibilities to each position. Henan Energy Group has fully implemented a system requiring chief engineers of outburst mines to join the mine party committee and serve as executive deputy mine directors, granting them the authority to suspend work, mining faces, and personnel.

To improve supervision and inspection quality and efficiency, Anhui has strengthened preventive supervision, intervening early in the investigation of hidden disaster-causing factors, mining layout planning, and major disaster prevention and control. Timely major risk alerts are issued to address issues in disaster control processes, closing gaps in disaster management. Shaanxi has established coal mine gas supervision teams, deploying them to four gas disaster-prone mining areas for continuous guidance and support over the past 20 years.

Notably, Henan Energy Group has allowed reasonable adjustment periods for mines undergoing gas control by reducing production targets and extending control timelines. During the application of thin protective seam technology at Mengjin Coal Mine, the group adjusted its operational assessment targets. Hebi No. 6 Coal Mine suspended production for 18 months to comprehensively implement gas control. These measures enabled the mine to achieve a regular cycle of extraction, excavation, and mining.

The conference emphasized that gas control is a long-term and arduous task that allows no room for complacency. The National Mine Safety Administration called on all regions, regulatory and supervisory departments, and coal mining enterprises to implement the spirit of the conference with a focus on action and accountability, continuously improving the quality and efficiency of gas control and promoting the high-quality development of the coal industry