Madiliang Coal Mine Leads the Way in Intelligent Mining with Ten Smart Systems Deployment

The coal industry, as the cornerstone of China’s primary energy structure, has been undergoing a profound transformation from traditional manual mining to intelligent production amid the dual pressures of deep resource exploitation and frequent geological disasters. In 2020, coal accounted for approximately 56.7% of China’s primary energy consumption, and it is predicted to remain at around 50% by 2050, according to the Chinese Academy of Engineering. This enduring dominance underscores the urgency of achieving safe, intelligent and precise coal mining, especially as shallow coal resources are depleted and mining depths continue to increase. Against this backdrop, Madiliang Coal Mine, affiliated with Inner Mongolia Intelligent Coal Co., Ltd., has emerged as a pioneer in the industry by building and applying ten core smart systems for intelligent mining, redefining the production mode of coal mines with cutting-edge technologies such as 5G, the Internet of Things (IoT), big data and artificial intelligence (AI). The mine’s practice not only realizes the goal of reducing personnel and increasing efficiency in underground operations but also provides a replicable and referable engineering model for the intelligent construction of coal mines with similar coal seam occurrence conditions across the country.

China’s coal mining industry has evolved through five distinct stages: manual or simple mechanical mining, primary mechanization, comprehensive mechanization, automation and intelligent mining, and is currently in the initial stage of intelligent mining, characterized by single-machine autonomous operation, real-time data updating and uploading, and remote human intervention. The breakthroughs in new-generation information technologies have provided solid technical support for the upgrading and transformation of coal mining from automation to intelligence. Different from automated mining, intelligent mining integrates three core elements: intelligent perception, intelligent decision-making and intelligent control, enabling mining equipment to real-time perceive and analyze the working environment, make independent decisions and implement precise control, and thus realize adaptive adjustment according to changes in the working environment. Although domestic and foreign scholars have conducted extensive research on coal intelligent mining and achieved rich results, most of these research achievements lack specific elaboration on the actual application of key intelligent mining technologies in coal mine production practice. Madiliang Coal Mine has filled this gap by combining its own production needs and geological conditions, taking the concept of “managing equipment is managing production, and managing data is managing equipment” as the core, and carrying out in-depth exploration and practice of intelligent mine construction.

Located in Jungar Banner, Inner Mongolia Autonomous Region, Madiliang Coal Mine has a designed production capacity of 5 million tons per year, with the No.5 coal seam as its main mining seam, whose recoverable thickness ranges from 0.80m to 16.07m. The mine features low gas content and moderate hydrogeological conditions, and adopts the fully mechanized top-coal caving longwall retreat mining method along the strike. The 507 fully mechanized caving face is the intelligent mining face of the coal seam, equipped with high-performance mining equipment including ZF23600/29/45D hydraulic supports, MG900/2400-QWD shearers and SGZ1000/2×1200 scraper conveyors. Faced with the pain points of traditional coal mining such as difficulty in recruiting workers, high labor intensity of underground workers, low sense of well-being and harsh working environment, Madiliang Coal Mine has launched the intelligent construction project by investigating key intelligent mining technologies at home and abroad and tackling key problems of intelligent construction in cooperation with equipment manufacturers. The mine has built a four-tier intelligent mining mode consisting of a decision-making and command layer, a production execution layer, a data acquisition layer and a basic equipment layer, realizing a mining mode dominated by independent perception, analysis, decision-making and control of equipment and supplemented by remote human intervention. At the heart of this mode lies the ten smart systems, which cover all aspects of coal mine production, transportation, management, sales and logistics, forming a closed loop of intelligent operation for the entire mine.

The intelligent scheduling and remote centralized control system is the “nerve center” of Madiliang Coal Mine’s intelligent operation, solving the long-standing problems of real-time underground video transmission and communication in traditional coal mines. By leveraging 5G, big data, industrial ring networks and IoT technologies, the mine has built a unified intelligent scheduling and remote centralized control platform, which integrates an emergency alarm center, a rescue command center, a video monitoring center, a video communication center and a data analysis center. High-definition cameras are deployed at all underground production operation sites, and multiple business monitoring subsystems are established based on common operation scenarios such as working faces and belt conveyors. Terminal devices collect video data of the operation scenarios 24 hours a day, and the collected data is uploaded to the ground in real time through a multi-level communication network with a unified communication protocol standard. Relying on AI service technologies, the system analyzes the operation behaviors in various scenarios, realizing functions such as dead-angle-free, full-video communication scheduling and full-video monitoring of underground equipment. The monitoring and early warning cover all links of the mine, enabling high-quality management with low cost and a small number of personnel, ensuring orderly mine operation command without conflicts between departments, and laying a solid foundation for the safe production of the mine.

The equipment intelligent early warning and remote consultation system has broken the traditional “two shifts of production and one shift of maintenance” working system of coal mines, realizing the transformation from production management to data management. The system is composed of three subsystems: equipment whole-life cycle management, equipment intelligent inspection and equipment remote consultation. The equipment whole-life cycle management subsystem is equipped with a fault monitoring and diagnosis system for all key mining equipment, which monitors and analyzes the key operation data of the equipment in real time to realize real-time diagnosis and early warning of the equipment’s health status. When abnormal data is detected, the system will alarm in a timely manner and notify relevant personnel to carry out targeted maintenance and overhaul of the equipment. The equipment intelligent inspection subsystem deploys intelligent inspection robots at all key underground locations, which collect high-definition and infrared images of roadways and working faces and transmit the information to the ground in real time, allowing technical personnel to judge the operation status of equipment and the surrounding environment on the ground. The equipment remote consultation subsystem builds a cooperation platform between the mine and equipment manufacturers and sets up an expert team. When insoluble faults occur, the mine conducts remote consultation with the technical personnel of the manufacturers through the platform, sharing real-time operation status and operation parameters of the equipment, so as to realize timely and effective handling of equipment faults. The application of this system has not only eliminated the maintenance shift but also liberated a large number of production labor forces, fundamentally improving the efficiency of equipment management and maintenance.

The intelligent coal mining system is the core of Madiliang Coal Mine’s intelligent production, which has completely changed the traditional working mode of the coal mining face with high noise, high dust concentration and frequent accidents, and realized the production mode dominated by autonomous control of mining equipment and supplemented by manual remote intervention on the working face by applying 5G, memory cutting and remote intervention technologies. The mine has reduced 15 personnel per shift on the mining face, and only 5 to 6 personnel are actually needed on the working face, achieving significant results of reducing personnel and increasing efficiency. In terms of 5G technology application, considering that intelligent mining needs to collect a large amount of sensor data and video monitoring data, the mine deploys base stations in a remote manner and installs them with an external antenna coverage method in two directions. The data transmission adopts the mode of shearer → CPE (Customer Premise Equipment) → 5G network → MEC (Mobile Edge Computing) server → CPE → shearer controller, realizing the application of 5G communication networking for shearers. At the same time, the mine uses 5G network slicing technology to flexibly respond to different network application scenarios of the working face, ensuring the stability and high efficiency of data transmission. The memory cutting technology relies on inertial navigation, shearer rocker arm and traction part sensors to collect key data such as the shearer’s attitude, position, mining height, walking speed and body inclination in real time. After technical personnel complete a demonstration coal cutting cycle through remote control, the shearer enters the memory cutting mode and realizes the memory cutting function according to the coal cutting data stored in the demonstration cut. The remote intervention technology equips the shearer with a CS-Rlink 5G redundant network control device for shearers. With the help of underground high-definition PTZ cameras and the advantages of 5G’s high bandwidth and low latency, the system feeds back the production status of the working face in real time through the working face monitoring interface, and analyzes and processes the working condition data such as the shearer’s trajectory, speed, left and right cutting heights, pick temperature and cutting motor current in real time through the shearer monitoring interface. When the mining environment changes and the equipment cannot make independent decisions and control, the staff carry out remote intervention through the shearer operation console in the ground centralized control center, modify the cutting route and coal mining process, realize the remote control function of the shearer, and ensure the safe and efficient production of the working face.

The intelligent heading system addresses the problem of unbalanced mining and heading caused by the relatively low level of intelligent construction of the heading face compared with the coal mining face in the current coal mine industry. The system uses multi-directional sensors to accurately measure the pose information of the roadheader in real time, including three-dimensional coordinate position, course deviation angle, pitch angle and roll angle. It uses a total station to indicate the equipment navigation route and an inertial navigation device to realize automatic deviation correction, ensuring that the roadway is accurately formed according to the designed path. Relying on 5G technology, the system enables personnel to carry out accurate remote control on the ground, realizing functions such as automatic positioning, memory cutting, fault self-diagnosis, near-ground remote control and ultra-long visual operation. On the premise of not reducing the monthly single heading level of the heading face, the system has realized unmanned heading operation and fewer people in anchor protection operation, effectively solving the problem of mining-heading imbalance and ensuring the continuous and stable production of the mine.

The intelligent belt transportation system has realized the green and intelligent transportation of coal by solving the problems of idling, overload and deviation of belt conveyors in traditional coal transportation caused by uneven coal mining volume, which easily lead to equipment damage and energy waste. The mine deploys intelligent inspection robots for belt conveyors in the main transportation roadway. The front end of the robot is equipped with a mine intrinsically safe network camera and a searchlight, and the lower part is equipped with a retractable camera lifting frame and an infrared thermal imaging camera. The ground monitoring center receives the real-time images collected by the robot, establishes a basic image database, and conducts digital calculation, processing, analysis and comparative learning on the real-time images to generate prediction results, realizing real-time monitoring of the operation status of the belt conveyor. When abnormal situations such as belt deviation, coal piling, foreign matters, edge biting and edge tearing occur, the robot will alarm in a timely manner. In addition, the robot is equipped with a wireless charging device to ensure the continuous cruising ability of the equipment. The application of intelligent inspection robots has replaced the traditional manual inspection, eliminating the problems caused by human factors such as visual fatigue, inattention and negative attitude of inspectors, and improving the safety and efficiency of coal transportation.

The unattended integrated coal quality transportation and sales control system has innovated the traditional coal sales mode, realizing the whole-process unattended operation of transportation vehicles from mine entry, loading to ticketing. The system is composed of five subsystems: entrance management, remote metering, remote loading, exit management and transportation and sales information management, which solve the problems of vehicle entry, weighing, loading, exit, data processing and statistics in traditional transportation and sales respectively. All links such as information release, contract signing, order assignment and order grabbing are carried out online, and the production plan is adjusted in real time according to the transportation plan. The mine has canceled the underground coal bunker, simplified the production system, and realized the “no coal contact” in the whole transportation process, which not only reduces potential safety hazards but also practices the management mode of “production based on sales and linkage between production and sales”, completely eliminating the occurrence of underweight sales and ensuring the economic benefits of the mine.

The intelligent traffic safety control system has upgraded the traditional manual control of auxiliary transportation to system control, effectively ensuring the intrinsic safety of underground auxiliary transportation. The system is composed of an access control system, a traffic light and acousto-optic alarm system, and a positioning and monitoring system, which realizes real-time monitoring of underground vehicles and personnel. The access control system automatically conducts the “four over-limit” detection (overlength, overwidth, overheight and overweight) on trackless rubber-tyred vehicles when they enter the mine, and vehicles that fail the detection are not allowed to enter the mine. The traffic light and acousto-optic alarm system is reasonably installed at all underground cross roadway entrances and important locations. According to the data of the vehicle positioning system and the principle of “first come, first served”, the system real-time controls the display mode of traffic lights, avoiding vehicle meeting, traffic jam and even collision at curve locations. The positioning and monitoring system equips all underground vehicles and personnel with positioning cards, and builds a person-vehicle positioning and monitoring system together with the detection base stations and control systems arranged underground, which real-time displays the position and speed of personnel and vehicles, and automatically records the vehicles and personnel with illegal operation through system calculation and analysis.

The Internet + remote office system has broken the limitations of the traditional office mode with complex document approval and signature processes and low efficiency, realizing paperless remote office and creating a home office mode for the mine. The system covers all fields of coal mine production, sales, logistics and support, realizing the online and intelligent management of the mine. During the COVID-19 epidemic in 2020, the mine only had 110 on-duty personnel to complete the production plan of 18,000 tons of raw coal per day, which fully verified the high efficiency and flexibility of the system, and provided a reliable guarantee for the continuous production of the mine under special circumstances.

The IoT + intelligent storage and express service system has solved the problems of large floor space, long time consumption and low efficiency of traditional coal mine material storage, which is managed manually for both storage and logistics. By applying mine precise positioning, AGV (Automated Guided Vehicle) intelligent robots and IoT technologies, the system records the information of articles in the process of warehousing, outbound and transportation into the data network, realizing the three-dimensional transformation of flat warehouses, improving warehouse capacity and increasing cargo positions. The system has replaced the traditional manual operation with intelligent equipment, realizing the intelligentization of storage operations. Madiliang Coal Mine only needs 1 warehouse keeper and 3 feeding personnel (including drivers) to meet the material purchase, storage and distribution needs of the entire mine, greatly reducing the enterprise’s investment in labor costs and improving the efficiency of material management and logistics distribution.

The intelligent ventilation system has realized the energy-saving and intelligent ventilation of the mine, solving the hidden danger that improper manual adjustment of traditional underground ventilation may lead to insufficient fresh air volume and accumulation of harmful gases at operation sites in a very short time. Based on the existing ventilation monitoring system, the mine has built a monitoring module for real-time data transmission to ensure that all underground air flow data are monitored by the system at all times. The decision-making module receives the air flow data through an exclusive network channel, uses the built-in algorithm of the module to compare whether key indicators such as air flow and air pressure are within the reasonable fluctuation range of the mine air flow safety indicators, and puts forward an air flow adjustment scheme according to the calculation results. The control module remotely controls ventilation facilities such as pneumatic air doors, pneumatic air windows and local fans by receiving the air flow adjustment scheme, changes the direction and size of air flow, makes the mine ventilation meet the production needs, keeps the ventilation system in a dynamically optimal state, and reduces the concentration of harmful gases to a safe level, fundamentally ensuring the safety of underground personnel and production.

The construction and application of the ten smart systems have brought remarkable economic and social benefits to Madiliang Coal Mine. The mine has realized the safe and efficient production of coal, greatly reduced high-risk operation posts, canceled the traditional maintenance shift and underground coal bunker, simplified the production operation process, improved production and transportation efficiency, and reduced the energy consumption per ton of coal. However, the practice of Madiliang Coal Mine also reveals that the current intelligent mining of coal mines in China still faces a number of key problems that need to be solved urgently, which are also the common challenges faced by the intelligent construction of the entire coal industry.

First of all, the ideological concept of relevant personnel in coal mines needs to be transformed urgently. Most of the current workers and leaders of intelligent coal mines in China have engaged in traditional coal mine work for a long time, with conservative ideological concepts, reluctance to innovate and lack of trust in intelligent equipment. They hold the wrong view that the more people there are in working faces and other places, the fewer mistakes will be made, which runs counter to the original intention of promoting intelligent mining in China. Therefore, it is imperative to strengthen publicity and training, change the traditional ideological concepts of coal mine workers and leaders, and establish a new concept of intelligent production.

Secondly, the initial investment in intelligent mining is large and the input-output ratio is unbalanced. The short-term benefits of intelligent mining are not obvious, which makes some coal mines hold a wait-and-see attitude towards intelligent mining, and even regard it as a “face project”, resulting in a weak willingness to carry out intelligent construction. To promote the intelligent mining mode on a large scale, it is urgent to establish an objective, professional and real evaluation method that can reflect the input and benefits of coal mine intellectualization, so as to provide a scientific basis for coal mines to carry out intelligent construction.

Thirdly, the adaptability of the current intelligent mining mode is poor. At present, there are many intelligent mining coal mines in China, but their mining modes are only applicable under similar geological conditions, and have good effects in mines with simple coal seam occurrence conditions. However, intelligent mining cannot be realized in mines with complex conditions such as large coal seam dip angle, large undulation, high gas content, high ground stress and poor surrounding rock conditions. How to improve the adaptability of the intelligent mining mode to complex geological conditions has become a key problem that needs to be solved in the next step of the coal industry.

Fourthly, the talent training system for intelligent mining is not perfect. China’s intelligent mining started late, and at present only a small number of universities have set up relevant majors, and a clear and definite training system has not yet been formed. Intelligent mining requires the deep integration of equipment with AI, big data, industrial IoT and other technologies, which puts forward higher requirements for the professional quality of talents. How to train compound talents who master both coal mining professional knowledge and information technology has become an urgent problem to be solved by universities and the coal industry.

Finally, the innovation of key technologies and components of intelligent mining is insufficient. At present, many key components of coal mine intelligent mining equipment still rely on imports, and the independent research and development capacity needs to be further strengthened. In addition, the working environment of underground working faces is harsh, and high-definition cameras are easily affected by water mist, dust and other factors, resulting in the failure of personnel in the ground centralized control center to grasp the mining status of working faces in real time and effectively. It is necessary to optimize the design of visual algorithms and image processing technologies to improve the anti-interference ability of perception equipment.

In view of the above problems, the coal industry should take multiple measures to promote the in-depth development of coal mine intelligent mining. First, it is necessary to further enhance the mutual coordination between intelligent subsystems, break the information island between various systems, realize the interconnection and data sharing of all intelligent subsystems, and make the intelligent mining mode no longer limited by coal seam occurrence conditions. Second, it is necessary to accelerate the research and development and application of intelligent robots, develop special intelligent robots adapted to the harsh underground working environment of coal mines, and replace underground workers to carry out high-risk and heavy physical labor operations, so as to further realize the goal of unmanned underground mining. Third, it is necessary to strengthen the research and development of key technologies of intelligent mining equipment, improve the independent perception, analysis and decision-making capabilities of equipment, and make the equipment fully meet the requirements of autonomous operation, reducing the dependence on human remote intervention. Fourth, it is necessary to build a top-level architecture of intelligent coal mines and a big data application center, integrate the data resources of all links of coal mining, transportation and sales, realize the intelligent analysis and decision-making of the entire mine production and operation process based on big data technology, and improve the overall operation efficiency of the mine. Fifth, it is necessary to speed up the construction of the talent training system, strengthen the cooperation between universities, research institutions and coal enterprises, set up targeted majors and courses, cultivate a large number of compound talents for intelligent mining, and provide solid talent support for the intelligent development of the coal industry.

The intelligent mining practice of Madiliang Coal Mine is a successful exploration of the coal industry’s transformation and upgrading under the background of the digital and intelligent era. The ten smart systems built by the mine have covered all aspects of coal mine production and operation, realizing the transformation from traditional experience management to data management and from on-site manual operation to remote intelligent control. This practice not only brings tangible economic benefits to the mine but also provides a valuable engineering reference for the intelligent construction of coal mines with similar coal seam occurrence conditions in China. With the continuous breakthrough of new-generation information technologies and the in-depth promotion of the integration of the coal industry and digital technology, the intelligent mining of coal mines in China will surely break through the current technical bottlenecks and development difficulties, and move towards a higher level of unmanned (fewer people) mining, which will inject strong impetus into the high-quality development of China’s coal industry and ensure the stable supply of national energy.

Author Information: XU Rijie, YANG Ke (State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Huainan 232001, China; National and Local Joint Engineering Research Center of Precision Coal Mining, Anhui University of Science and Technology, Huainan 232001, China; Key Laboratory of Safety and High-efficiency Coal Mining of the Ministry of Education, Anhui University of Science and Technology, Huainan 232001, China); WU Jinsong, KAN Lei (Madiliang Coal Mine, Inner Mongolia Intelligent Coal Co., Ltd., Ordos 010499, China) Journal: Industry and Mine Automation, Vol. 47 No. 11, November 2021 DOI: 10.13272/j.issn.1671-251x.2021080034

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