China's coal mine dust treatment technology has made a major breakthrough

Pneumoconiosis is one of the most serious occupational diseases in China, especially in the mining industry. Since the statistical data, the cumulative reported cases of coal workers' pneumoconiosis accounted for nearly half of the total occupational pneumoconiosis. In recent decades, the annual new cases of coal workers' pneumoconiosis are more than 60%, and even as high as 80% in recent years, the resulting death toll far exceeds the death toll of coal mine production accidents.

"Dust has become the number one 'culprit' that endangers China's coal mine safety production and occupational health, and it is urgent to research and develop key technologies and equipment, as well as update policy standards." Yuan Liang, academician of the Chinese Academy of Engineering and president of Anhui University of Science and Technology, recently pointed out in an interview with reporters.

On November 12, the identification meeting of major scientific research projects of "Basic Research on Air Purification and occupational Health in Coal mines in Northern Shaanxi Province and Key technical equipment and Demonstration" was held simultaneously in Shenmu, Shaanxi Province, Huainan, Anhui Province, Xuzhou, Jiangsu Province, Wuhan, Hubei Province and Beijing. The project takes Shaanxi Coal Group Shenmu Hongliulin Mining Co., LTD. (hereinafter referred to as "Hongliulin Mining Company") as the research object. After two years of research and development, a series of industry initiatives have been achieved in the research and development and application of key technologies and equipment such as air quality monitoring, dust removal, dust control, exhaust gas purification, and personal protection. The safety, economic, environmental and social benefits are significant after field verification. After evaluation, the expert group unanimously agreed that the research results of the project series have reached the international leading level.

■■ Dust restricts the sustainable development of coal mines

Statistics show that by the end of 2021, China has reported a total of 1,025 million cases of occupational diseases, of which occupational pneumoconiosis is as high as 915,000 cases, and nearly half of occupational pneumoconiosis is coal workers' pneumoconiosis, which is not only irreversible, but is developing towards a younger age. In 2020, there will be 6,668 deaths due to pneumoconiosis in China, of which coal workers' pneumoconiosis may reach about 60%. It can be said that after gas, dust has become the number one constraint on the current safe production and sustainable development of coal mines.

"Dust is produced to varying degrees in the main production links of coal mining, excavation, transportation and hoisting, among which the dust produced by the mining face accounts for more than 85% of the whole mine." Yuan Liang told reporters that especially in the modern large mining operation environment, the local space PM2.5 concentration exceeds 260 times the maximum limit of PM2.5 in the ground air.

High concentration dust in coal mines will not only cause lung function decline, pneumoconiosis and COPD and other occupational diseases, but also affect the efficiency of coal mining work, and even cause coal dust explosion, coal dust and gas explosion and other safety accidents.

"In the coal industry, dust control and occupational disease prevention, prevention is the key. In the past, we have adopted various solutions to dust control, but none has fundamentally solved the problem of mine air pollution." Hongliulin mining company chairman Zhang Hong told reporters frankly.

In Yuan Liang's view, the current coal mine dust control and pneumoconiosis prevention and control work is still in the initial and medium-low speed development stage, facing many challenges such as insufficient cross-integration of science and technology and medicine, weak basic research, low level of occupational health security, lack of key technology and equipment, insufficient supervision and service capacity, and urgent updating of policy standards.

"The prevention and control of coal mine dust from the source is actually a major interdisciplinary problem, so the task of scientific research and innovation is arduous, and the training of high-end talents needs to be broken through, and multi-subject collaboration has become an inevitable requirement to promote the construction of coal mine dust prevention and control system and high-quality coal development." Mr Yuan said.

■■ Series of innovative achievements to fill the gaps in the industry

Based on the above understanding, in 2020, under the leadership of Yuan Liang and Zhang Hong, Hongliulin Mining Company and Anhui University of Science and Technology jointly set up 9 industry authority institutions, a total of more than 150 people to participate in the R & D team, the first time in the industry to adopt the industry-university-research, science and technology medical integration collaborative innovation model, with Hongliulin Mining as the research object. Basic research and key technical research on occupational hazards and health protection in coal mines have been systematically carried out.

Hongliulin Mining Company is a typical representative of China's super-large modern mine, which has high production efficiency and large quantity of underground vehicles, leading to serious occupational hazards such as dust, fuel and vehicle exhaust, and difficulties in prevention and control. Conditions in coal mines in the coal-producing provinces of Inner Mongolia, Ningxia and Xinjiang are similar, meaning the Hongliulin demonstration project is crucial to solving the world's challenges of underground air purification and occupational health.

Yuan Liang introduced that the current project has made a number of gratifying major breakthroughs. For example, at the theoretical level, the concept of underground air revolution in coal mines and the concept of "source-regional-classing-policy" treatment of dust in mining face areas were first proposed. The first large-scale physical simulation platform for air pollutant transport in confined space was developed to reveal the transport law of dust and fuel vehicle exhaust and the dust removal mechanism of fine water mist under the action of air flow field. The pathogenesis of lung inflammation and pulmonary fibrosis induced by exposure to coal dust and fuel vehicle exhaust pollutants was revealed, biomarkers of early health damage in miners were screened, the first coal mine dust exposure population cohort and biobank were established in China, and many gaps in the domestic coal mine dust population cohort were filled.

At the same time, the research team has also made a series of pioneering achievements in the construction of key technical equipment and systems. For example, it has developed a set of new technologies and equipment for efficient prevention and control of dust in the whole production chain of underground mining and mining areas of coal mines, as well as non-precious metal low-temperature catalytic oxidation efficient purification technology for pollutants from fuel vehicles, and efficient individual protection technology and related products; For the first time, the combined operation optimization system of underground fuel trucks based on exhaust emission and the online air quality monitoring and health intelligent early warning system of underground coal mine were developed.

At the appraisal conference, the expert group led by Wang Shuangming, academician of the Chinese Academy of Engineering and professor of Xi 'an University of Science and Technology, and Peng Suping, academician of the Chinese Academy of Engineering and professor of China University of Mining and Technology (Beijing), agreed that after the application and demonstration of the project series of research results in Hongliulin Mining, "remarkable economic and social benefits have been achieved." It has a wide range of promotion and application prospects "and" has reached the international leading level ".

■■ The integration of science, technology and medicine has achieved remarkable results

Talking about the changes brought by the project for Hongliulin Mining Company, Zhang Hong said: "Not only has the project solved the problem of controlling the large amount of dust produced by the coal cutting machine at the large mining height, the dust source is multiple and dispersed, and the coal dust is poor wettability, but the floating dust that was visible to the naked eye has been slightly invisible, and it is becoming a reality for miners to breathe fresh air in the 100 meters underground."

The relevant data show that after Hongliulin Mining Company adopts the above advanced technology achievements, the total dust removal rate of mine exceeds 91%; The CO purification efficiency of fuel vehicle exhaust is more than 70%, and the CH purification efficiency is more than 80%. Moreover, in the past two years, direct economic benefits of 85 million yuan have been obtained, with significant security, economic, environmental and social benefits.

Yuan Liang introduced that the above series of research results can not only be widely promoted and applied in similar mines across the country, but also have a wide range of application prospects in tunnel engineering and underground defense fortifications.

The reporter learned that Anhui University of Science and Technology has a medical school, with an integrated talent training system, as early as 2015, put forward the scientific concept of mine occupational health, committed to big data, artificial intelligence and 5G technology as the support, to build a mine smart health security system. In February 2019, with the approval of the Ministry of Education, the school was approved as the "Key Laboratory of Industrial Dust Control and Occupational Safety and Health of the Ministry of Education", opening the practice of integrating dust control and occupational safety and health "science and technology and medicine".

According to the "Strategic blueprint for Coal mine dust Prevention and Control and occupational safety and Health Development in the next 20 years" proposed by Yuan Liang in the medium and long-term consulting research project of the Chinese Academy of Engineering, the occupational life cycle health of mine employees will be basically realized in 2035, and the incidence of occupational diseases and the occupational life cycle health of personnel will be fully realized in 2050.

"We have roughly divided coal mine dust control and pneumoconiosis control into five stages, that is, by 2035, in terms of technology, policies, regulations and standards, it will be as popular as gas control in all coal mines in the country, so that China's mining workers are full of happiness and a sense of gain." Yuan Liang said.

"In the first phase, research and development is to carry out basic research in a single point of fragmentation at multiple coal mines. At present, in the second stage, the integration of science and technology and medicine, upstream and downstream linkage and systematic research are carried out around a mining area, and the 2.0 version of the solution is achieved with the above series of latest demonstration results as a symbol. Not long ago, we were approved the first "14th Five-Year" national key research and development plan in the field of occupational safety and health in China, and have reached a cooperation intention with Huawei. The next step will be to further carry out technical research and engineering demonstration in conjunction with the smart mine, and the short-term goal is to achieve nearly 100% dust reduction rate in the 3.0 version of the solution."