1. Development situation of China's aggregates industry 

Aggregate is the largest, indispensable and irreplaceable raw material for infrastructure construction in China, with an annual consumption of about 20 billion tons. It is the world's largest mineral product, raw material and bulk commodity. In the early days, extracting natural sand and gravel in the river or lake were main way of getting aggregates. With the gradual decrease of natural sand and gravel resources, the state government strengthened the construction of ecological civilization. Nowadays, the aggregates for construction of infrastructure projects were mainly from physical processing of ore in the quarry. There is no coal and chemical reaction during the process, thus carbon dioxide emission is low.

After years of large-scale extraction of land-won sand and gravel, the natural resources have gradually decreased. In recent years, the amount of sand from major domestic rivers has dropped sharply, and the number of enterprises has decreased significantly, resulting in a short-term imbalance between regional supply and demand, as well as a sharp rise in prices. Low-quality sand and gravel enter the market, increasing the cost of infrastructure construction, affecting the progress of construction and brings hidden dangers to quality and safety. It is urgent to take measures to properly solve the problems. With the tightening restriction of extracting natural sand and gravel resources and the increasing environmental protection, machine-made sand and stone (or crushed stone and manufactured sand) has gradually become the main source of aggregates for construction in China, and its proportion has now accounted for more than 80%.

The production of machine-made sand and stone has gradually changed from a simple and scattered manual or semi-mechanical workshop to a standardized and large-scale factory. China’s aggregates industry has entered a new era of high-quality development. However, the machine-made sand and gravel industry also faces outstanding problems such as weak quality assurance capability, unreasonable industrial structure, low level of green development, and partial supply and demand imbalance. Therefore, it is necessary for the industry to explore a green and low-carbon development path that can not only ensure sustained and stable economic growth, but also achieve carbon emission reduction.

2. Prediction and analysis of carbon peak and carbon neutrality in the aggregates industry

We need to accelerate the formation of a green development mode, coordinate the adjustment of industrial structure and energy structure, and further optimize the energy consumption structure of the aggregates industry; we need to develop and seek technical emission reduction paths and spaces, and explore new ways of low-carbon development of aggregates industry; we need to optimize the technology, develop low-carbon concrete technology and carbon absorption technology; we have to strengthen the source control of carbon emissions, speed up the process of eliminating outdated production capacity, and take effective measures to achieve multi-industry coordinated carbon reduction, synergistically build a circular economy industrial chain, and give full play to the specific conditions of the industry and enterprises. We need to give full play to the role of market mechanisms, integrate enterprise resources, cooperate with the government to promote social participation and promote the earlier realization of carbon peak and carbon neutrality of the aggregates industry.

By 2025, the industrial structure, resource structure and transportation structure of the aggregates industry will be significantly improved; the proportion of greening will be significantly increased, and the level of clean production will continue to improve; the comprehensive utilization system of resources will be improved; breakthroughs will be made in key technological bottlenecks, and a green technology innovation system will be gradually established. Before 2023, the industry will take the lead in realizing the carbon peak. The green and low-carbon management system of China's aggregates industry with distinctive features of “green mines, green factories, and green production bases” has basically taken shape.

By 2035, the endogenous driving force of green development will be significantly enhanced, the scale of green industry will reach a new level, the efficiency of resource utilization will reach the international advanced level, the ecological environment will be fundamentally improved, and the application of new generation technologies such as intelligent manufacturing of crushing equipment, intelligent mines, and 5G unmanned mines will be more mature. The whole process of mining, processing, transportation, management, data fusion will be more mature. The operation system of green supply chain will be more mature, and the green and low-carbon management system of the industry will have substantial breakthroughs.

3. Industry guidelines for the aggregates industry to achieve carbon peak and carbon neutrality

We need to optimize the layout of industrial green and low-carbon development, transform traditional high-energy-consuming equipment to reduce energy consumption; adopt high-efficiency energy-saving equipment in new quarries; improve equipment quality and prolong its service life, and reduce the use of disposable materials; be committed to restoration of abandoned mines to restore ecology and increase carbon sink capacity; extend industrial chain and reduce transshipment links; carry on recycling and comprehensive utilization of construction solid waste, tailings and waste rock to reduce the exploitation of primary mines.

Achieving carbon peak and carbon neutrality goal is a major decision and deployment made by the Party Central Committee and the State Council. It is an important political task that we need to be fully aware of its significance. It is important to build a mechanism featured by government -leading, and common practice of enterprises and individuals. We need to seize the opportunity and work hard, in order to promote pollution reduction and carbon reduction, as well as green and low-carbon transformation and development. We have to fight the battle of pollution prevention and control, and make our contribution in promoting the realization of carbon peak and carbon neutrality and build a Beautiful China.

4. Technical paths and methods for carbon reduction in aggregates industry

According to the “Opinions of CPC Central Committee and State Council on Completely, Accurately and Comprehensively Implementing the New Development Concept and Doing a Good Job in Carbon Peak and Carbon Neutrality”, “Carbon Peak Action Plan before 2030” and other relevant national policies, it is necessary to understand that to achieve the goal, we have to build consensus among all parties, strengthen concentration of factors and form synergy; it needs to strengthen unified leadership and establish a working mechanism; it needs government leadership, enterprise main body, and industry self-discipline to form a good combination of upper and lower linkage, departmental coordination, and joint management.

Government level
Local governments should adjust and optimize the aggregates development layout, formulate quarry mining plans, improve product supply capabilities, promote the transformation and upgrading of the industrial structure, build green mines, and comprehensively promote the high-quality development of the industry. Governments need to follow the “four adherences”: adhere to protection priority, adhere to strict access, adhere to changing methods, and adhere to reform and innovation; follow five principles: the principle of planning first, the principle of ecological priority, the principle of protection priority, the principle of policy in place, and the principle of ensuring production; realize the goals of four modernizations: intensive, large-scale, green and intelligent.

On the premise of planning first, we need to strengthen the rational layout, scientifically set the number of machine-made sand and stone enterprises in county-level cities, prefecture-level cities and provincial capital cities according to the actual situation such as resource endowment, market demand of infrastructure construction and logistics conditions, and encourage taking advices from industry associations’ think tanks. The new production capacity should not be less than 1 million tons per year in principle. We need to comprehensively promote the construction of green mines, reorganize and integrate, standardize the market, strengthen mining in accordance with laws and regulations, crack down on illegal and arbitrary mining, and form industry self-discipline.

Industry level
First, we should continue to vigorously promote the integration of quarry resources, optimize the industrial structure, and speed up the construction of green low-carbon management systems such as green mines, green factories and green production bases. We need to vigorously promote the construction of green transportation and integration centers, actively recommend the use of green advanced technologies, processes and equipment in the national encouraged catalogue, strengthen resource recycling, reduce carbon emission intensity, promote the green and low-carbon development of aggregates industry, encourage afforestation in the whole industry and increase carbon sink capacity.

Second, we need to strengthen cleaner production and improve the level of comprehensive utilization of resources to reduce carbon emissions. We need to strengthen the treatment of waste water and dust in aggregates producing enterprises, and do well in recovery and disposal of stone powder and tail mud and comprehensive utilization of resources. We should implement the requirements of “Opinions on promoting the high-quality development of the Manufactured aggregates industry” and “The guiding opinions on promoting the healthy and orderly development of the aggregates industry”, and adopt carbon sink measures and carrying out mine restoration. Through the adoption of new technologies, new processes, new equipment and the utilization of new clean energy, through the ecological restoration of waste stone mines and the extension of the industrial chain, we can form a mode of integrated development of aggregates 4.0 + mode in which primary, secondary and tertiary industries deeply integrated, increasing the new development momentum of the industry, and maximizing the application of carbon sink measures such as quarry greening and ecological industrial park. Therefore, the aggregates industry can give play to the advantages of “carbon neutrality”. By 2025, we will build more than 100 intelligent, green, high-quality and well managed green quarry bases.

Third, we need to vigorously develop green technology and strengthen scientific and technological innovation. The aggregates industry should vigorously develop green technologies and equipment with short process, low energy consumption and low emission, adopt new rock drilling and perforation technology, and encourage green production and green transportation. We have to promote the application of new technologies such as intelligent mines, digital factories, artificial intelligence, big data, Internet of things, industrial robots, digital twins and 5G, so as to realize the data integration and decision optimization of the whole process of mining, processing, transportation and management, and form a green supply chain. If condition permitted, aggregates producing enterprises shall adopt off-peak production and make use of low power at night as much as possible to achieve scientific power consumption.

Fourth, we need to accelerate the upgrading of technology and equipment and promote the application of new technologies and equipment. We need to speed up R&D of the intelligent, efficient and environmentally friendly technical equipment, increase the proportion of clean energy use, focus on supporting the R&D of key technologies and equipment for resource utilization such as stone powder and waste rock, and accelerate its industrialization process. Based on industrial policies, standards and norms, we need to strengthen self-discipline and eliminate backward equipment and processes characterized with high energy consumption, non-compliance with environmental protection and low comprehensive utilization efficiency. According to the actual situation of the quarry, we should use wind energy, photovoltaic power and potential energy for power generation, and use potential energy of conveyor belt to generate power so as to to save energy. We need to adjust and optimize the industrial product structure, promote the R&D, production and application of green and low-carbon products, and improve the green and low-carbon development level of the industry.

Enterprise level
According to the concept of the full life cycle, in the mine design stage, we need to consider the implementation of greening in various links such as equipment manufacturing, production, transportation and logistics, so as to reduce the adverse impact on resources and environment in the full life cycle of mine operation, and explore and implement a new green development model.

Enterprises should continue to promote green and low-carbon transformation and development according to the development requirements of the industry and in combination with its own the actual situation. And they need to work hard on the following aspects:

First, continue to adjust and optimize the industrial structure and carry out green layout; Second, strengthen the research, development and application of green and low-carbon technologies and equipment; Third, gradually use wind energy, solar energy, potential energy and other new clean energy; Fourth, increase the recycling of large tailings, waste rock, stone powder, soil, construction solid waste, waste equipment and wear-resistant parts; Fifth, speed up the integrated construction of green mines, green factories, green bases, green parks and green supply chains; Sixth, carry out restoration and afforestation of mines to improve the carbon sink capacity of ecosystem.

Written by Hu Youyi(胡幼奕), Yang Xiaodong(杨晓东), Zhao Jing(赵婧)