In recent years, the scale of China's building materials industry has been expanding, the structure has been gradually optimized, and the ability of innovation, green and sustainable development has been significantly enhanced, which has played a positive role in economic and social development and the improvement of people's livelihood. Among them, the sand and gravel industry as the main building materials industry, the development is particularly rapid.
Driven by the closure and rectification in recent years, the scale and concentration of sand and gravel mines have improved, but the number of super-large, large and medium-sized sand and gravel mines is still small, accounting for only 5% of all sand and gravel mines. It will take time; for the strict requirements of the ecological environment, whether to choose simple measures to shut down all, or to make great efforts to rectify and upgrade, the local government is wavering, the shelving of some large and medium-sized sand and stone mining projects that originally met the requirements has further intensified the contradiction between supply and demand and increased the difficulty of integration.
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During the "13th Five-Year Plan" period, the development of the mechanism sand and gravel industry has made great progress, accounting for nearly 70% of the total construction sand and gravel, but the rapid development of the industry has exposed many problems. Small-scale mines in China account for a large proportion, and small-scale mines generally have problems such as insufficient cost investment and low enthusiasm for environmental protection measures. At present, the industry is severely polarized in production, management, environmental protection, and ecological sustainability. Some enterprises have low production mechanization and automation, environmental protection measures are not in place, and they do not pay enough attention to the coordinated and sustainable development of mine ecology and economy. On the other hand, the structural adjustment of the mechanism sand and gravel industry has been accelerated, but the industrial concentration is still low, the level of green development of the industry is low, the level of intensification and modernization is not high, and the overall investment in mine reclamation, ecological restoration, and greening is not high. Some enterprises still have the problem of unorganized discharge of dust and wastewater, insufficient attention to the efficient use of low-carbon energy, and the pollution discharge of fixed and mobile sources that need to be strengthened governance. On the whole, there is still a big gap in the industry to achieve high-quality development and meet the overall requirements of national green and low-carbon development.
In order to solve the outstanding problems of mine ecological restoration, such as many historical debts, many practical contradictions, and insufficient investment, on December 17, 2019, the Ministry of Natural Resources issued the Opinions on Exploring the Use of Market-oriented Methods to Promote Mine Ecological Restoration. At the same time, in order to improve the high-quality development of the sand and gravel industry, on November 11, 2019, the Ministry of Industry and Information Technology, the National Development and Reform Commission, the Ministry of Natural Resources, the Ministry of Ecology and Environment and other ten departments jointly issued the ''About Promoting the High Quality of the Mechanism Sand and Gravel Industry Several Opinions on Development "put forward specific development goals for the mechanism sand and gravel industry, and made it clear that mechanism sand and gravel enterprises should adhere to develop green mines in accordance with relevant specifications; strive to form a relatively complete and reasonable mechanism sand and gravel supply guarantee system by 2025; cultivate more than 100 intelligent, green, high-quality, and well-managed enterprises. Opinions were issued in a timely manner to further accelerate the development of China's non-metallic sand and gravel mining industry towards high quality. On June 28, 2019, the Green Mine Environmental Protection Professional Committee of the International Ecological Economy Association, led by the academicians of the Chinese Academy of Engineering Hao Jiming, Chen Yong, Wang Jinnan, and the State Council Counselors Jiang Minglin, Zhang Hongtao, etc., issued my country's first ''National Green Mine Environmental Protection and High-quality Development of Non-metallic Sand and Gravel Industry Demonstration Standards Construction Guide'' also provides an example for industry norms and high-quality demonstration construction.
In order to better play the incentive role of mine ecological restoration, while protecting the green water and green mountains, and promoting the high-quality development of social economy, it should be the first choice to integrate and upgrade the waste mines, and construct according to the national green mine high-quality standards to achieve resources Efficient use. The integrated ecological restoration of mines should follow the following principles: First, green mining should be used to achieve comprehensive recycling of resources and zero emissions. The second is to build a garden-style mining area by combining dynamic greening, ecological restoration and environmental re-cultivation. The third is to realize the precise management of the utilization of geological and mineral resources reserves by means of technical automation and management informatization. The fourth is to use the type of complex green, according to the governance model of suitable agriculture, suitable farming, suitable scenery, to achieve land intensive, production and city linkage. Local governments better fulfill their environmental and social responsibilities, and have greater achievements in resource development, ecological restoration, land use, and urban function improvement.
With the development of the trend of mine resource integration in China, the traditional mode of "small scale, large quantity and low efficiency" will be eliminated and innovated. The existing sand and gravel mining enterprises need to take the high-quality construction of green mines as an opportunity to speed up the whole process application of energy conservation and environmental protection.
China's non-metallic sand and gravel mining industry needs to strengthen the efficient application of energy conservation and environmental protection measures to promote the early realization of high-quality development of the industry.
Measures for efficient utilization of mining and production resources
First of all, the sand and gravel mine should take green mining as the overall requirement, combine clean production and green storage technology, realize the overall layout of green and modern science and technology of the source and process, and put an end to the traditional extensive development mode and production method. Secondly, through technical means, the level of sand and gravel resource utilization efficiency is improved, and the unit production efficiency is improved with the level of high-tech equipment. For sand and gravel mining and utilization, it must be dried and squeezed, and the side materials and surplus materials produced in the production process Realize 100% utilization, no tailings are left, and all become resource utilization, such as: stone powder collection can be used to produce cement and concrete, clay powder is used for new wall raw materials or environmental protection engineering construction materials around the mining area, etc.; for the main, common and associated resources of the mining area in the early stage to do a comprehensive survey, set up a comprehensive mining and utilization plan, to high-quality use, cascade utilization as the principle, improve the overall benefit as the overall goal. Finally, for the topsoil and residue produced in mining, 100 is used in combination with environmental treatment, pipe trench backfilling, original landform restoration, land reclamation, etc. For a large amount of sediment in sand and gravel production wastewater, sludge cleaning and dewatering processes are adopted to separate water and sediment and then be used as resources respectively, and the sediment is used for surrounding ecological utilization. Sand and gravel ore from ecological resources, should be 100 percent full utilization.
Energy saving and energy efficient application measures
According to the country's requirements for promoting the green and low-carbon transformation of energy development, my country's energy supply methods have also changed to green, efficient, safe and stable, close to users, and local materials. The sand and gravel mining industry needs to establish a low-carbon energy application layout plan and establish a full-process Energy consumption monitoring and accounting system; using the Internet of Things, informatization and automation technology management system to achieve the purpose of energy saving, power saving and money. This is also an inevitable trend of technological development.
How to reasonably plan to reduce the energy consumption in the process of mining, production and overall operation, and realize the synchronous operation of energy saving, electricity saving and economic benefits, this is not only a matter that mining enterprise managers must consider, but also a problem that the industry must pay attention to and the government and competent departments must pay attention. It is very important to strengthen the energy saving and efficiency in the production of mining area. For example, the selection of advanced energy-saving and high-efficiency construction machinery will benefit the long-term investment at one time; in the automatic operation, the energy recovery system will be added, and potential energy power generation technology can be used to save electric energy in the mining area with large drop; the gravity potential energy can be continuously recovered in the mining process to improve the energy recycling efficiency. For example, in the top-down transportation process of mineral materials, with the increase of mineral materials on the conveyor belt, the gravity of the mineral material itself gradually increases along the component force of the conveyor belt, so that the conveyor belt pulls the roller to accelerate the rotation, so that the gravity potential energy can be recovered and generated by the roller-driven generator; in addition, in the selection of mining technology, new blasting technology and blasting energy efficiency measures are adopted; according to the natural conditions of different mining areas, solar energy, wind energy, geothermal energy, etc. can be selected to achieve multi-energy complementarity; promote the planning of transportation links and the green and low-carbon transportation of vehicles, for example, set up closed pipelines from the mining area to the transfer station or adopt new energy transportation vehicles, etc. In addition, the mining area can also use photoelectric conversion to realize LED full-automatic lighting and domestic electricity consumption, and qualified enterprises can also make full use of biomass energy as supplementary energy for heating or canteen gas supply in the mining area. In short, it is necessary to take comprehensive measures and means to form a global high-efficiency energy application model in mining areas.
Environmental protection measures and ecological harmony in sand and gravel mines
Mine environment refers to the collection of environmental factors such as atmospheric environment, surface water environment, groundwater environment, acoustic environment, ecological diversity and so on, which are affected by mining activities. Mine environmental protection is the environmental evolution, destruction and pollution caused by the interaction and influence between mining activities and the environment.
The environmental protection measures of sand and gravel mines are mainly aimed at the mining process and production process. It is necessary to strengthen the treatment of waste gas, waste water, noise, solid waste and ecological environment, as well as the prevention and balance of the impact on biodiversity. At the same time, combined with the monitoring of the application of new technologies in the mine ecological environment, a general management and control system for environmental protection is formed. Through environmental monitoring, it accurately, timely and comprehensively reflects the current situation of environmental quality and the development trend of ecological impact, and provides scientific basis for mine environmental management, control and supervision of pollution sources.
In the mining process, adopt new blasting technology, such as millisecond control technology, electric control energy centralized release technology, etc., adopt precise measures, use blasting powder reduction method, and select fully automatic water mist humidification and dust removal, sound wave atomization dust reduction, magnetic water dust reduction, pre-charged high-efficiency spray dust reduction and other technologies, which can effectively reduce dust generated in the mining process; In production, establish a fully enclosed processing plant with an efficient dust collection system inside, it is conducive to the implementation of dust suppression, dust reduction and other measures in the factory. No open stockyard is set up in the mining area, and the loading and unloading of the stockyard are all carried out in a closed environment to prevent air pollution. For the treatment of wastewater, 100 of the wastewater is recycled in the mining process. At the same time, it can be fully combined with mine water as a supplement. After harmless disposal, the domestic water in the mining area can be used for greening and other utilization measures to meet the five hundred index requirements, dust pollution control and 100 does not constitute a pollution source affecting the air environment index, so that the domestic sewage treatment and harmless rate of 100, surface water environmental quality compliance rate of 100, wastewater recycling rate of 100, sludge harmless treatment and utilization rate of 100.
In the process of ore mining, low-noise equipment is selected and damping materials, seismic isolation materials and silencers are installed on the equipment to reduce the generation of noise sources. At the same time, the mining area shall strengthen the construction of isolation belts with surrounding villages or residential areas, and reasonably adjust and manage the production and transportation time to avoid disturbing the residents. The fully enclosed aggregate processing plant equipped with sound insulation materials can control the noise generated in the production process to the greatest extent, to the greatest extent, the noise should be controlled within a reasonable range, and at the same time, through the measures of enterprise-local harmony and the close contact of party building at the grass-roots level in mining areas, we should do a good job in the co-construction, co-creation and co-grasping of ecological civilization.
Solid wastes and garbage in mining areas and living areas are stored and managed according to industry and life. 100 percent of the side materials and surplus materials in mining and production in mining areas have been utilized as resources. The main source of industrial solid waste is to solve the harmless disposal of chemical substances such as waste oil from engineering equipment and energy storage batteries. Special closed storage places should be set up to mark hazardous wastes and a third party with treatment qualification should be entrusted for centralized treatment; domestic waste should be transferred to the municipal centralized waste transfer station for unified disposal; from the source of governance and take systematic, process-based disposal measures, leaving no hidden dangers; through the establishment of garden-style mining areas, actively become a local display window.
In view of the problems that the development and exploitation of mineral resources may damage the vegetation of mines and nearby areas, affect the living environment of organisms, and bring hidden dangers to regional species diversity, long-term monitoring of the ecological environment of mining areas can be carried out to find potential harmful and toxic substances in time, avoid ecological pollution and environmental impact, effectively control and improve the ecological environment of mining areas and nearby areas, and provide normal space for the survival and development of organisms; the changes of animal and plant species in the mining area indirectly reveal the changes of the survival factors (such as air and water) in the mining area. This is also one of the goals of environmental protection of sand and gravel mines, that is, to strengthen the protection of biodiversity in the mining area and nearby areas. It is also an important manifestation of whether the atmospheric environment and water environment have been destroyed.
In general, the energy-saving, environmentally-friendly and efficient application of my country's non-metallic sand and gravel mining industry is an inevitable requirement for the industry to move towards high-quality development, and it is also a need for the construction of ecological civilization; the development of cities and the construction of infrastructure are inseparable from sand and gravel raw materials, and the current sand and gravel industry The environmental pressure faced by some places, and even the implementation of "one size fits all" measures to stop ", directly lead to a serious imbalance, in 2018, the general office of the Central Committee issued a document requiring the inspection to be reduced by 50%, so as to solve the problems of various names and high frequency of supervision work in the sand and gravel industry, so as to create a relaxed policy environment for the sand and gravel industry; through the implementation of energy conservation and emission reduction, clean production, specialization, standardization, greening, industrialization, intensification, digitization and intelligence of environmental protection work, And pay attention to ecological balance, enterprise local harmony and other measures in the process, it is very necessary to establish an industry demonstration and leading system, with the concept of energy conservation, environmental protection and efficient application, to deal with the contradiction between sand and gravel mining development, production and ecological protection, and it is also realistic and urgent.
(About the author: Chen Yafei is the vice chairman of the Green Mine Environmental Protection Professional Committee of the International Ecological Economy Association; Peng Suping is an academician of the Chinese Academy of Engineering, a professor at China University of Mining and Technology, and a doctoral supervisor)
Website Editor: Gong Li
