Clean Processing and Utilization of Coal: 40 Years of “Whitening” Journey”

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Clean Processing and Utilization of Coal: A 40-Year Journey of Progress. Author/Source: Huahua Network – Coal Chemical Industry. Date: 2019-01-04. Clicks: 51. The clean processing and utilization of coal can be divided into four main development stages: a difficult start from 1978 to 1990, growth and expansion from 1991 to 2000, rapid development from 2001 to 2010, and transformation and upgrading from 2011 to 2018. “Over the past 40 years since the reform and opening up, the coal industry has evolved from coal processing and washing, as well as comprehensive utilization of resources, to the reclamation of land in mining areas, backfill mining, water-conserving mining practices, and efforts to reduce emissions and energy consumption. It has further advanced towards cleaner use of coal, the development of circular economy industrial parks, and ecological restoration in mining areas, thereby enriching the concept of green development in the coal sector. This approach has enabled the industry to pursue a path where resource exploitation in mining areas goes hand in hand with environmental protection, and where economic and social development is aligned with ecological benefits. ”Liang Jiakun, Secretary of the Party Committee and Vice President of the China Coal Industry Association, said this at the 5th China International Exhibition on Clean and Efficient Coal Utilization held in November this year. 40 years: coal, from fuel to raw material; mining areas, from black to green ； 40 years was a period during which those in the coal industry worked hard to ensure **energy supply, as well as to try to give coal a better image. Specifically, the clean processing and utilization of coal can be divided into four development stages: a difficult start from 1978 to 1990, growth and expansion from 1991 to 2000, rapid development from 2001 to 2010, and transformation and upgrading from 2011 to 2018. The difficult starting phase (1978–1990): Moving from single coal production to the “two transformations”. Starting in 1979, in order to implement the policy of “adjustment, reform, rectification, and improvement” put forward by ****, the coal industry underwent its second major restructuring since the founding of the People’s Republic of China. In 1986, the former Ministry of Coal Industry designated diversified operations as one of the three main pillars, alongside coal production and capital construction, and diversified operations focused on comprehensive utilization within the coal industry were launched on a full scale. During this period, coal enterprises began to shift from a single-business model to a diversified one, and from merely producing coal to engaging in its processing, washing, and comprehensive utilization. At the initiative of Gao Yangwen, then Minister of the Coal Industry, and with the approval of the former **Economic Commission, the China Coal Processing and Utilization Association was officially established on October 26, 1982. This marked the emergence of a specialized institution at the top level of the coal industry to promote coal processing and comprehensive utilization. During this period, efforts by enterprises to save energy and reduce emissions as well as basic environmental protection measures were strengthened. Most key coal enterprises established specialized departments for energy conservation and environmental protection, and the work related to energy efficiency, environmental protection, and the comprehensive utilization of coal entered an organized development phase. During this period, coal washing and processing developed rapidly, with the capacity to process raw coal increasing significantly. In 1978, there were 99 coal washing plants nationwide, with a total capacity to process 103.22 million tons of raw coal per year ； In 1990, there were 198 coal washing plants nationwide, with a capacity to process 254.36 million tons of raw coal per year, which was 1.5 times higher than in 1978. Automation in coal washing plants is beginning to take off, with some of these plants already using computers for production process control, data processing, and direct regulation. Since the late 1970s, coal quality testing in coal enterprises has gradually returned to normal. By 1985, 400 coal quality testing laboratories had been established in the key coal enterprises across the country. To ensure the rational utilization of coal resources, from the 1970s to the 1980s, China gradually established a coal quality testing system and a coal classification system. Over 40 standards were formulated, including the “Methods for Sampling Commercial Coal”, thus forming a relatively complete standardization system for coal quality. In the 1980s, the **standard for the Classification of Chinese Coals** was introduced, laying the foundation for coal production and its rational utilization. In terms of the conversion and utilization of coal, research and development efforts in areas such as coal coking, gasification, and pulverized coal compaction are continuing to advance. In the 1980s, to meet the coal needs for coking at Shanghai Baosteel, China’s coal resources were utilized in a rational manner by mixing Yanzhou’s low-ash, low-sulfur, and weakly cohesive bituminous coal, thereby producing coke suitable for use in large blast furnaces. Water-coal slurry is in the early stages of industrialization as a substitute fuel for oil. Under **unified promotion, energy-saving and upgrading initiatives for coal enterprises have been carried out on a comprehensive scale. Following the assessment, 56 enterprises in the coal industry were rated as Grade ** first-class energy-saving enterprises, while 344 were rated as second-class ones. The power supply in the coal mining area has been upgraded from 380 volts to 660 volts, and most of the key equipment for lifting, transportation, ventilation, and drainage in the mine has been renewed or upgraded. In the early days of reform and opening up, the coal industry carried out organized and planned comprehensive efforts to address environmental pollution. In 1983, the former Ministry of Coal Industry established an environmental protection leadership group and an environmental protection office. By the end of 1985, a three-tier management structure consisting of the Ministry of Coal, the coal administration bureaus (companies) at the provincial (autonomous region) level, and the mining bureaus had been established in coal mines under national allocation across the country. There were also 33 coal environmental monitoring stations at the ministry, provincial (autonomous region), and mining bureau levels. A preliminary environmental protection management system for the national coal industry has been established. In terms of comprehensive resource utilization, significant progress has been made in the technology for generating electricity using low-calorific-value fuels such as coal gangue, which is one of the most notable signs of this progress. On November 6, 1975, the Chongqing Yongrong Mining Bureau built the first power plant in China to burn low-calorific-value fuels such as coal gangue and medium-grade coal, successfully testing the first 20 steam tons per hour boiling furnace. Subsequently, the Gaokeng Power Plant of the Jiangxi Pingxiang Mining Bureau and the Didao Power Plant of the Heilongjiang Jixi Mining Bureau were built and put into operation one after another. The 6-megawatt stone coal power plant in Yiyang, Hunan, can stably burn stone coal with a calorific value of 950 kcal/kg. It is a comprehensive utilization power plant in China that uses fuel with the lowest calorific value. By 1988, the coal industry had built 14 coal gangue power plants, with a total installed capacity of 146,000 kilowatts. Various building materials can be produced using coal gangue and furnace ash. At the same time, progress has also been made in the utilization of mine gas for purposes such as producing carbon black and formaldehyde as civilian fuels. The Laohutai mine, formerly part of the Fushun Mining Bureau, extracted over 100 million cubic meters of gas per year. This gas was used not only for heating and cooking in the homes of 32,000 miners but also as a fuel source for 60,000 residents in Fushun city. Coal companies also use coal and its derivatives to produce lignite wax, activated carbon, and carbon products. According to incomplete statistics, from 1978 to 1985, through the comprehensive utilization of coal mine waste across the country, approximately 9 billion coal gangue bricks were produced, over 4 million tons of gangue cement was manufactured, more than 1.4 billion kWh of electricity was generated from coal gangue, and over 1.2 million tons of iron sulfide was recovered. A range of products resulting from the comprehensive development and utilization of coal, such as vanadium pentoxide, activated carbon, and high-alumina clay, have entered the international market. By 1990, the total value of diversified operations across the entire industry reached 8.7 billion yuan, with over 1.3 million people employed in these diversified activities. Development and Growth Phase (1991–2000): Diversified operations centered around comprehensive utilization projects developed rapidly. In 1993, the State Council made the major decision to liberalize coal prices, marking the full entry of coal enterprises into the market. During this period, the former Ministry of Coal Industry, building on the concept of \"three main pillars,\" further formulated a development strategy for the coal industry centered on coal production, combined with diversified operations and comprehensive development. With the support of the interest-subsidized loan policy for coal mine restructuring, the comprehensive utilization of coal has developed rapidly. The proportion of operating income from non-coal industries in the total operating income of enterprises continues to rise. Diversified operations centered around resource comprehensive utilization projects have developed into one of the three major pillars, on a par with coal production and capital construction. This stage marks the entry into a period of stable development, during which the level of coal preparation technology improves and its scale expands. The coal separation technology utilizing large-scale dense-medium cyclones developed independently in China has been widely applied. Composite dry coal separation technologies and equipment have also been developed, leading to the construction of a number of large-scale, modern coal preparation plants equipped with advanced technologies and equipment. By 2000, there were 1,584 coal washing plants across the country, with a coal processing capacity of 521.99 million tons per year. Energy conservation and emission reduction have entered a stage of deeper development. The coal industry has strengthened the scientific management of energy. Coal mines have implemented an energy consumption assessment system for various processes. Grade standards and assessment methods have been established for energy consumption in six major processes: fans, water pumps, hoists, air compressors, belt conveyors, and boiler rooms. Grade-based assessments are now carried out. In 1992, **energy-saving technological upgrades were implemented for fans and water pumps in the coal industry, as a pilot project to use the savings in electricity consumption to repay loans. After 4 years of effort, the pilot program was successful and rolled out nationwide. During this period, significant changes occurred in environmental protection: there was a gradual shift from end-of-pipe treatment to control throughout the entire production and construction process; an emphasis shifted from focusing solely on concentration control to addressing both concentration and total volume control; and there was a transition from dealing with scattered point sources of pollution to a combination of centralized and decentralized control methods. A four-level environmental protection management system for the coal industry has been basically established, and a three-level coal environment monitoring network plays a significant role in protecting the coal industry’s environment. The implementation rate of the “three simultaneities” system for environmental protection in coal construction projects has reached 100%. The national coal industry has seen an additional wastewater treatment capacity of 290 million tons per year, bringing the total capacity to 835 million tons per year ； The new waste gas treatment capacity is 3.6 billion cubic meters per year, bringing the total capacity to 12 billion cubic meters per year ； 4,500 hectares of land have been reclaimed from underground mines, and 1,770 hectares from surface mines. Of the 387 self-ignited gangue piles counted, 262 were brought under control and extinguished, resulting in a control rate of 68%. With the shift in the focus of coal production and construction, the emphasis of environmental protection efforts has begun to shift to ecologically vulnerable mining areas in the northwest. In terms of comprehensive resource utilization, by vigorously developing diversified operations that make use of various resources, efforts are made to implement the State Council’s directives regarding industrial restructuring, reducing staff while improving efficiency, and turning losses into profits. In 1993, the newly established Ministry of Coal Industry specifically established the Department of Comprehensive Utilization and Diversified Operations. **A loan subsidy policy is implemented for the coal industry to strongly support coal enterprises in developing comprehensive utilization and diversified operations. From 1993 to 1997, a total of **13 billion yuan in interest-subsidized loans were allocated as startup funds. Overall, over 20 billion yuan was invested across the industry to develop more than 2,500 comprehensive utilization and diversified business projects. Special efforts were made to help 10 enterprises facing severe difficulties due to depleted resources—such as those in Jiaozuo and Pingxiang—to shake off poverty and overcome their hardships.** Meanwhile, the coal industry has developed a large number of new technologies, such as circulating fluidized bed co-combustion of coal gangue with coal slime and sintered hollow bricks made from coal gangue, which have promoted the rapid development of comprehensive utilization of coal resources. By the year 2000, the coal industry had built and put into operation 120 power plants utilizing low-calorific-value fuels such as coal gangue and coal slurry, with a total installed capacity of 1.84 million kilowatts ； The volume of gas extracted from underground wells was 820 million cubic meters, with 440 million cubic meters being utilized ； 45 briquette factories have been built, with a production capacity of 500,000 tons per year ； 35 coking plants, with a production capacity of 15 million tons per year ； There are 7 coal-water slurry plants, with a production capacity of 1.28 million tons per year. Rapid development phase (2001–2010): A coal-based industrial chain and a circular economy development model were established. Entering the 21st century, with changes in the demand for coal both domestically and internationally, the processing and utilization of coal accelerated its process of innovative development. The scale of coal washing and processing has continued to expand, and significant progress has been made in shifting from rough coal processing to more advanced processing methods. The traditional model of comprehensive resource utilization in the coal industry has gradually evolved into a development model based on coal-based industrial chains and circular economy. Coal enterprises have shifted from relying solely on energy conservation measures to adopting technical solutions, managerial approaches, structural optimizations, and comprehensive energy management strategies; as a result, energy consumption per unit of production has decreased significantly, giving rise to a large number of environment-friendly coal enterprises. The rapid development of coal processing, comprehensive utilization, as well as energy conservation and environmental protection has significantly improved the quality and efficiency of the coal industry’s development. The washing and processing of coal has entered a period of rapid development. Since the 11th Five-Year Plan introduced the policy requiring that all newly built large and medium-sized coal mines must be equipped with coal washing plants, this has **promoted the construction of such plants, especially those for thermal coal. By 2010, the total number of coal preparation plants in our country had reached over 1,800, with a processing capacity for raw coal of 1.78 billion tons per year. There are already over 20 coal washing plants that employ efficient heavy medium coal separation technology, with a processing capacity of more than 10 million tons per year. The maximum processing capacity per plant for coking coal washing plants is 12.5 million tons per year, while that for thermal coal washing plants is 31 million tons per year. The national raw coal processing capacity increased from 521.99 million tons per year in 2000 to 1.78 billion tons per year in 2010. Over the decade, it rose by 2.4 times, with an average annual increase of over 100 million tons. Such a pace of development is unique in the world. Energy conservation and emission reduction are beginning to develop in a standardized and institutionalized manner. “During the 11th Five-Year Plan period, **energy conservation and emission reduction were set as mandatory targets; initiatives were launched to encourage energy savings in a thousand enterprises, as well as activities to standardize energy efficiency, thereby further reinforcing the primary responsibility of coal enterprises to reduce energy consumption. Upon evaluation, among the 62 key coal enterprises included in the energy conservation initiative for 1,000 enterprises, 59 have met or exceeded their annual energy conservation targets, accounting for 95.2%. In terms of environmental protection, the level of environmental pollution control in the coal industry improved significantly during this period. The environmental-friendly enterprise recognition program, which was launched in 2007, effectively motivated coal enterprises to take action on environmental protection, leading to a significant improvement in their environmental conditions. Industrial pollution sources in key state-owned coal mines have been generally addressed. According to incomplete statistics, the rate of compliant pollutant discharge in key large and medium-sized coal mines across the country exceeds 95%; over 20% of large coal enterprises have achieved zero pollutant emissions. The fire suppression rate for spontaneously burning gangue piles is 90%, while the land reclamation rate is 36%. Many mining areas have carried out comprehensive environmental management. In the remediation of coal-mining subsidence areas, efforts have been made to expand the area covered by green vegetation, achieving notable results. In terms of comprehensive resource utilization, during this period, based on the pilot projects in ** and other regions, coal enterprises developed their own distinctive models for circular economy development, tailored to their specific circumstances. The circular economy in the coal industry is showing a prosperous and rapidly developing trend. The construction of coal circular economy parks not only expands the scope and meaning of traditional comprehensive coal utilization but also significantly improves the level of such utilization. Building on the significant development in the comprehensive utilization of coal during the \"Eighth Five-Year Plan\" and \"Ninth Five-Year Plan\" periods, during the \"Tenth Five-Year Plan\" and \"Eleventh Five-Year Plan\" periods, in line with the goals and requirements of establishing a modern enterprise system, the coal industry restructured and upgraded a number of projects that were initially established – projects that were small in scale, technologically backward, and had poor economic efficiency. Projects that suffered heavy losses and had no market demand were shut down or merged. As a result, a group of key projects and enterprises with high levels of technological expertise, large-scale production, and good economic performance were created; some of these even became the main drivers of the economy in mining areas, paving new paths for the transformation and revitalization of those areas whose resources had been depleted. During this period, the industrialization and scaling up of comprehensive utilization in the coal industry saw significant improvement, through the development of demonstration projects for the comprehensive use of coal mine waste such as coal gangue, mine water, coalbed methane, and oil shale, as well as associated mineral resources. In 2010, the generating capacity from coal gangue reached 23 million kilowatts. The comprehensive utilization rates of coal gangue, mine water, and coal mine methane reached 60.8%, 59%, and 38.5% respectively. Transformation and upgrading phase (2011–2018): Promoting the transition of coal from a traditional energy source to a clean energy source. Since the * of the Party, the coal industry has actively implemented strategic initiatives for ecological civilization construction, vigorously advancing the development of eco-friendly and beautiful mines; as a result, a large number of “garden-style” green mines have been established. Energy-saving, low-carbon, green, and environmentally friendly technologies such as replacing coal with gangue, backfill mining, water-conserving mining in western mining areas, oxidation of waste gas, and utilization of low-concentration gas have been promoted and applied in these mining areas. A range of technologies for the clean and efficient conversion and utilization of coal, such as its classification and use based on quality, new types of coal chemical processing, and ultra-low emission systems for coal combustion, have reached international leading levels. The development of green and ecological mines, as well as the clean and efficient conversion and utilization of coal, have become one of the most prominent indicators of the transformation and upgrading of the coal industry during this period. They have made significant contributions to promoting a revolution in energy production and consumption, facilitating the transition of coal from a traditional energy source to a clean energy source, and ensuring the healthy, scientific, and sustainable development of the coal industry. In terms of coal washing and processing, the scale of coal preparation plants is further expanding, and their capacity is increasing. In 2017, there were over 2,300 coal preparation plants in operation across the country, with a total capacity to process 2.7 billion tons of raw coal. Actual amounts of raw coal processed amounted to 2.47 billion tons, giving a processing rate of 70.2%. Modern coal washing is evolving toward higher quality, greater efficiency, energy savings, and cleaner operations. The manufacturing of coal washing equipment has developed into a systematic industry, with its standards continuously improving. International exchanges in coal washing are continuously expanding, strengthening cooperation with the coal washing community around the world and contributing to the improvement of coal washing technology and management standards in China. In terms of energy conservation and emission reduction, the regulatory framework for energy management in the coal industry has been further improved. A number of industry standards have been issued and put into effect, including the \"Certification Requirements for Energy Management Systems in the Coal Mining and Processing Industry,\" the \"Energy Consumption Limits per Unit of Output for Underground Coal Mining Enterprises,\" the \"Energy Consumption Limits per Unit of Output for Open-Pit Coal Mining Enterprises,\" the \"Power Consumption Limits for Coal Processing,\" the \"Requirements for the Provision and Management of Energy Measurement Instruments in Coal Enterprises,\" and the \"Standards for the Statistics of Energy Consumption in Coal Enterprises.\" The establishment of energy management systems has been fully implemented in key state-owned coal mines, improving the enterprises’ energy management capabilities. The energy consumption per unit of product produced has been on a downward trend; in 2017, the comprehensive energy consumption per ton of raw coal produced by key coal enterprises was 16.2% lower than it was in 2010. In terms of the development of green and ecological mines, during this period the coal industry earnestly implemented the principles set forth by the Party, making efforts to promote the construction of an ecological civilization in coal mining areas. To meet the needs of evolving circumstances, the Environmental Protection Working Committee formerly under the China Coal Processing and Utilization Association has been reorganized into the Coal Mine Ecological Development Branch. The entire industry has carried out initiatives to create ecological civilization coal mines, with 7 coal mines in three batches passing the pilot evaluation. Technologies such as coal gangue backfill mining, water-retaining mining, coal and gas co-mining, and underground gangue disposal have been applied. A large number of coal mine parks such as Huaibei **Mine Park** and Tongmei Jinhuagong **Mine Park**, along with newly built employee residential complexes and green industrial plazas, have been established, resulting in a significant improvement in the environmental conditions of the mining areas. In terms of the clean and efficient conversion and utilization of coal, during this period, the coal industry made comprehensive progress in various areas such as the intelligent development of coal washing and processing (dry coal cleaning), the scientific and orderly advancement of modern coal chemical industries, the green upgrading of traditional coal chemical processes, low-carbon innovation and development, energy conservation, environmental protection, and comprehensive utilization in mining areas, as well as the graded and quality-based utilization of lower-grade coal. Innovative and industrialization demonstration projects have been developed, including a complete set of technologies for building green coal mines, key technologies for high-efficiency comprehensive mining on a scale of tens of millions of tons, heat pump heating and cooling technologies using waste air from coal mines and mine water as energy sources, technologies for liquefying oxygen-containing coalbed methane (LNG), a complete set of technologies for oxidizing waste gas, and technologies for generating electricity from ventilation gas (waste air). These projects have promoted innovation and industrialization in technologies for the clean and efficient use of coal. Developing the modern coal chemical industry is one of the main ways to achieve clean and efficient conversion of coal as well as to promote industrial transformation and upgrading. During this period, following the commissioning of the world’s first million-ton-scale coal direct liquefaction plant, another 3 160,000-ton-scale coal indirect liquefaction plants, 3 large-scale coal-to-olefins plants, 1 200,000-ton-scale coal-to-ethylene glycol plant, the first phases of 2 coal-to-natural gas projects with an annual capacity of 4 billion cubic meters, as well as a demonstration project for coal indirect liquefaction with an annual output of 4 million tons, were successively built and put into operation. This marked significant breakthroughs in China’s modern coal chemical technology, processes, and equipment. In addition, new development models such as the integration of coal power generation with coal-based chemical feedstocks have been promoted, and significant progress has been made in addressing environmental pollution associated with coal consumption, including ultra-low emissions from coal-fired power plants and measures to control the use of scattered coal. Through the joint efforts of the entire industry, the path for the clean and efficient conversion and utilization of coal has become clearer, making significant contributions to the green, low-carbon, and circular development as well as the transformation and upgrading of the coal industry in the new era.