The Current Status and Prospects of Energy Conservation, Emission Reduction, and Clean Production in the Cement Industry

1. The current situation of China’s cement industry

China is a major producer and consumer of cement, and its cement output has consistently ranked first in the world in recent years. As one of the most fundamental raw materials for economic development, no material—either domestically or internationally—has yet been able to replace cement’s pivotal role. The cement industry has also become an important benchmark for measuring a country’s level of national economic and social development as well as its overall strength. Since the implementation of the reform and opening-up policy, China’s domestic economic construction has continued to expand, and with the acceleration of urbanization, the cement industry has experienced rapid growth.

Although China’s cement industry has developed relatively rapidly, many problems have emerged during this period of rapid growth. The main issues include low industry concentration—many cement producers remain small in scale, their products are of relatively low quality, and a significant number of cements fail to meet national standards. Some enterprises still rely on outdated production technologies with low technological content, yet they account for a considerable share of the market. Additionally, the spatial layout of the cement industry is irrational, leading to uneven distribution of production capacity. Cement manufacturers consume large amounts of energy, resulting in severe resource waste and serious environmental pollution. Despite China’s active promotion of new dry-process cement technology, many small-scale cement producers continue to use outdated methods such as small vertical kilns and wet-process kilns. These obsolete processes are highly energy-intensive and fail to make efficient use of heat, thereby driving up the overall energy consumption of China’s cement industry. The primary environmental impacts of the cement industry stem from dust and gaseous emissions. Cement-related dust emissions represent a substantial portion of total industrial dust emissions in China. Currently, smoggy weather conditions are becoming increasingly common in China, and the country is placing greater emphasis on environmental protection. Under stringent government regulations, although cement dust emissions have gradually declined, the pollution problem remains severe. Therefore, it is imperative that the cement industry promptly undertake clean production audits.

2. Clean Production in the Cement Industry

Clean production in the cement industry refers to the adoption of advanced process technologies and equipment, enhanced quality management, rational use of raw materials and fuels, and the full utilization of all available waste resources—provided that such practices comply with relevant standards—during the cement production process. This approach aims to improve the efficiency of resource and energy utilization, reduce or eliminate pollutant generation, lower greenhouse gas emissions, ensure that product performance and quality meet national standards, and guarantee that the products are non-toxic and harmless to both humans and the environment during their use. As a “high-energy-consuming, high-polluting, and resource-intensive” industry, the cement sector primarily impacts the environment through pollution caused by cement and clinker production, as well as ecological damage resulting from mining activities. Therefore, it is evident that implementing clean production in the cement industry not only helps reduce energy and material consumption and minimize pollutant emissions but also contributes to mitigating ecological damage in mining areas, enhancing the comprehensive utilization of resources, improving enterprise productivity, lowering production costs, and boosting market competitiveness—thus yielding significant environmental, economic, and social benefits.

The role of cleaner production in the cement industry:

(1) Implementing cleaner production can double the effectiveness of environmental protection in the cement industry, significantly reducing its environmental burden.

(2) Implementing cleaner production can prevent pollution at the source, simplifying complex processes and focusing on easier tasks, thereby reducing the technical difficulty of environmental protection efforts in the cement industry.

(3) Preventing pollution through cleaner production methods can save substantial funds compared to simply treating pollution at the end-of-pipe stage.

(4) Preventing pollution through cleaner production methods can conserve resources and energy, reduce product costs, and enhance economic benefits, thereby boosting enterprises’ enthusiasm and initiative in pollution control.

(5) Cleaner production is the foundation of the circular economy.

Cleaner production has fundamentally transformed the past passive and reactive approaches to pollution control. It integrates product manufacturing, use, environmental burden reduction, and pollution prevention into a comprehensive, lifecycle-wide approach, thereby reducing the overall environmental footprint and minimizing adverse environmental impacts throughout the entire product lifecycle. Cleaner production emphasizes proactive, integrated prevention measures taken before pollution occurs, effectively preventing or mitigating both pollution generation and its environmental impacts. Numerous domestic and international practices have demonstrated that this proactive approach can conserve resources and energy, yielding significant economic benefits. Therefore, implementing cleaner production is the most effective means of fundamentally controlling pollution, reducing risks to both humans and the environment posed by industrial activities, and promoting the coordinated development of industrial production and environmental protection.

3. Current Cement Clean Production Technologies

Currently, the most commonly used clean production technologies in the cement industry include:

(1) Vigorously develop large-scale, advanced dry-process cement production technology. Constructing new kilns, expanding existing ones, and upgrading old kilns to incorporate external decomposition systems—increasing the proportion of cement produced via the advanced dry process—is a key approach to enhancing the technological level of cement production and reducing energy consumption. (2) The application of pure low-temperature waste heat power generation technology allows for full utilization of the waste heat from the kiln preheater and grate cooler exhaust gases. This technology can achieve an energy recovery rate of 35–40 kW·h per ton of clinker.

(3) The adoption of a low-resistance, high-efficiency multi-stage preheater system, a new type of grate cooler with flow-control features, and multi-channel coal-injection pipes can all effectively reduce the thermal energy consumption in cement clinker production.

(4) Replace inefficient ball mills with high-efficiency grinding machines to reduce power consumption in the grinding process. Grinding is the primary energy-intensive step in cement production, accounting for approximately 70% of the total energy consumption. Previously, most Chinese cement enterprises relied on inefficient ball mills with an efficiency rate of only 3% to 5%. Today, vertical mills, roller presses, compression mills, and ultra-fine mills have largely replaced the traditional ball mills. Larger mills are being used in place of smaller ones, and small ball mills with diameters less than 1.83 meters are being phased out. Additionally, grinding process flows are being optimized by adding pre-crushers and classifier machines, and wear-resistant steel balls, wear-resistant liners, and energy-efficient liners are being adopted.

(5) Meanwhile, the cement industry is actively promoting enterprise scaling, with production equipment trending toward larger sizes and production processes moving toward automation and intelligentization. Through these effective measures, significant energy-saving and consumption-reducing benefits have been achieved. In the cement distribution sector, it is essential to develop high-efficiency, low-loss logistics systems such as bulk cement transportation and to establish robust recycling and utilization systems for waste and used construction materials. The successful application of these new technologies has greatly propelled technological progress in society. These advancements ensure that cement hydrates and hardens properly according to architectural design requirements, enabling the structural density of cementitious materials to meet the quality standards required for construction projects.

4. Optimization of the production process

Promote technological innovation and actively develop energy-saving and emission-reduction technologies to provide the technical foundation for achieving “reuse” of cement products and the cement industry.

(1) Transform the grinding process and develop advanced grinding technologies to reduce power consumption. In cement production, approximately 3 to 4 tons of various materials need to be crushed for every ton of cement produced, and the power consumption during the crushing process accounts for 60% to 70% of the total production power consumption. Selecting advanced crushing processes, simplifying the crushing flow, improving traditional crushing operation methods, enhancing grinding efficiency, and reducing grinding power consumption have become key factors in achieving energy savings and reducing consumption in cement production. Therefore, cement enterprises can initiate ecological transformations of their grinding processes by focusing on three areas: upgrading pre-crushing processes before the mill, modifying the interior of ball mills, and retrofitting classifiers, thereby realizing energy savings and consumption reduction.

(2) Develop new dry-process cement technology to ensure high-quality cement products and achieve energy conservation and emission reduction in the cement industry. The new dry-process cement refers to a cement production process that employs an off-kiln decomposition technique. Its core technologies include suspended preheaters and off-kiln decomposition, as well as the use of advanced raw material and fuel homogenization methods, energy-efficient grinding technologies and equipment. The entire production line is equipped with computer-based distributed control systems, enabling automated, efficient, high-quality, low-consumption, and environmentally friendly cement production. This technology boasts several advantages: rapid production, high thermal efficiency, greater output per unit volume compared to wet-process cement, and lower heat consumption. Developing this new dry-process cement production technology not only allows for the utilization of industrial waste residues and a certain amount of municipal solid waste but also—compared to shaft kilns—increases labor productivity by 5 to 6 times, reduces energy consumption significantly, and limits dust emissions to just 1/5 to 1/10 of those from shaft kilns. Moreover, the quality of the cement produced is stable, with high strength grades.

(3) Establish an ecological industrial chain to achieve “resource utilization” in cement industry enterprises. Drawing inspiration from the food chains and food webs of natural ecosystems, transform one enterprise’s waste (output) into another enterprise’s raw materials (input), thereby forming a “symbiotic industrial chain.” This creates a closed-loop system in which material and energy flows are comprehensively coordinated and synergistically integrated—a principle of symbiosis among enterprises. This is what we call the “ecological industrial chain.” It is both an energy conversion chain and a material transfer chain. Material and energy flows move sequentially through the levels of the “ecological industrial chain,” forming a three-dimensional cyclical structure among raw materials, energy sources, waste, and various environmental elements. Energy and resources circulate repeatedly within this structure, maximizing their utilization and enabling waste to be transformed into valuable resources with added value.

5. Development Trends in the Cement Industry

5.1 Structural Adjustment of the Cement Industry

Our country advocates sustainable development, and the cement industry has now reached a stage of overcapacity across the entire sector, necessitating large-scale structural adjustments and industrial upgrading. In the future, the development of the cement industry should follow a policy of “controlling total output while adjusting the structure.” Specifically, total output should meet societal demand, while simultaneously optimizing the industrial structure of the cement sector—eliminating small cement production enterprises and supporting the growth and enhanced competitiveness of larger companies. In the future, outdated production lines characterized by unstable product quality and failure to meet environmental standards will be phased out, while new technologies will be widely adopted. Cement enterprises will also shift from a quantity-oriented approach to a quality-oriented one, moving from extensive to intensive operations. Ultimately, this will lead to a regional market structure dominated by large conglomerates, enabling the industry to transition from pursuing increased volume to focusing on value creation.

5.2 Strengthen technological innovation in the cement industry

An enterprise’s capability for technological innovation is crucial to achieving industrial upgrading and fostering new drivers of economic growth. In China’s cement industry, technological innovation must be given top priority. Cement producers should, on the one hand, establish and improve a comprehensive system for independent innovation, set up innovation platforms, and increase investment in independent innovation. On the other hand, they should actively attract advanced talent and technologies and intensify efforts in integrated innovation. Traditional industries should be transformed through the adoption of cutting-edge technologies, new processes, and advanced equipment. It is essential to closely monitor global trends in scientific and technological development as well as market demands, and to enhance product quality by focusing on energy and resource conservation and reducing environmental pollution.

5.3 Focus on the production of high-quality cement

Although China’s cement industry as a whole suffers from overcapacity, most of the production consists of ordinary cement, while high-quality cement is scarce, resulting in a significant gap in demand for premium cement. Moreover, there is a strong correlation between the strength grade of concrete and the quality of cement: for every one-grade increase in concrete strength, the amount of cement and steel reinforcement required decreases by 10% to 15%. By using high-quality cement, we can reduce resource consumption, thereby aligning with China’s policies on energy conservation, emission reduction, and sustainable development standards.

5.4 Developing the Green Cement Industry

Green industrial development in the cement industry refers to cement enterprises that not only avoid causing negative impacts on human society and the environment but also actively contribute positively to them. In the future, China’s cement industry will undoubtedly move toward green industrial development. First, we must maximize resource utilization. From the perspective of current cement production technology, there is no need for exceptionally high-quality raw materials; lower-grade raw materials can be used as substitutes for clay and limestone in the mix, thereby conserving resources. Second, we should adopt green energy sources and combustible waste fuels, fully harness renewable resources, and enhance the utilization of waste heat—using it to generate electricity—thus meeting the requirements of sustainable development. Finally, we must strengthen the treatment of pollutants. All cement production enterprises are required to install and operate reliable electrostatic precipitators with high dust-collection efficiency, significantly reducing dust emissions and minimizing air pollution. Only by achieving green industrial development can cement enterprises ensure their long-term survival and prosperity.

6. Conclusion

The cement industry has enormous opportunities and potential for cleaner production. From raw material processing to finished-product shipment, and from senior management to frontline operators, everyone needs to actively engage and participate in their respective roles. Only by ensuring that every process and every stage of enterprise production is optimized can the implementation of cleaner production truly yield tangible results and enable enterprises to enjoy stronger market competitiveness. It is imperative and urgent to accelerate energy-saving and emission-reduction efforts in cement enterprises. By applying the theory of circular economy and guided by the “3R principle”—reduce, reuse, and recycle—we can achieve “reduction” in the cement industry through cleaner production; promote “reuse” via technological innovation; establish ecological industrial chains to facilitate “recycling” of cement; and leverage government policy guidance—all of which will help identify an effective pathway for advancing energy-saving and emission-reduction initiatives in Guizhou Province’s cement enterprises. The principle of recycling represents an end-of-pipe approach. By transforming waste back into resources, we can reduce the volume of final waste disposal, maximize resource utilization, and return materials that have already fulfilled their initial use value back to factories, where they are processed and reincorporated into new products. This is what we commonly refer to as waste recovery and comprehensive waste utilization. The “3R principle” production model takes a holistic approach, addressing pollution control at every stage—from design and raw materials to processes, technological advancements, and production management—thus minimizing pollutant emissions during production, reducing harm to both the environment and human health. At the same time, it enhances the overall efficiency of resource utilization, lowers enterprise production costs, boosts economic benefits, and safeguards the ecological environment.