in Tongchuan are the main raw materials for the production of cement. As the pillar industry of building materials industry in Tongchuan, the cement industry has brought rapid economic development and created economic benefits, but at the same time, it has also become the main source of pollution affecting the quality of the city's atmospheric environment. To this end, the Municipal Bureau of Ecology and Environment has set up a research group, which has conducted in-depth research and discussion on seven cement enterprises and seven independent cement grinding stations, to understand the environmental pollution situation of enterprises in detail, to analyze the causes of the problems, and to put forward targeted treatment proposals, so as to promote the performance upgrading of cement enterprises and help the city's environmental air quality continue to improve.
1. In the
past 10 years, Tongchuan City has implemented the transformation and upgrading of traditional industries, comprehensively applied environmental protection measures such as national policies, emission standards and pollution reduction, and successively implemented the projects of "Chuankou Breakthrough", "National Highway Struggle" and "Yaowangshan Encirclement and Annihilation". Fifty-seven backward cement production lines have been closed down and dismantled, creating a "prestige model" of "seven sections and one reduction". The number of cement clinker enterprises in the city has been reduced from more than 30 to 7, and the production capacity has increased from 4.2 million tons to more than 20 million tons, thus realizing the rebirth and rapid development of pillar industries in pollution control.
There are seven cement enterprises in Jidong, Shengwei Building Materials, Yaobai Special, Satisfaction, Yaowangshan Ecology, Fenghuang Building Materials and Shengwei Special, and nine clinker production lines, with a daily output of 48000 tons of cement clinker. There are seven independent cement grinding stations in Jidong Cement, Lishan Building Materials, Mine Cement, Sunyuan Cement, Dongli Cement , Xuanyuan Cement and Xinyuan Building Materials, with an annual output of 5.9 million tons of cement.
In 2023, 14 cement enterprises in the city actually produced 10.6 million tons of cement clinker and 11.403 million tons of cement, consumed 1.3127 million tons of desulfurized gypsum, 1.23 million tons of coal, 1.738 million tons of water and 843.66 million degrees of electricity; Among them, 7 cement enterprises produced 10.6 million tons of cement clinker and 10.25 million tons of cement, consumed 1.254 million tons of desulfurized gypsum, 1.23 million tons of coal, 1.675 million tons of water and 759.3 million degrees of electricity; Seven independent cement grinding stations produce 1.153 million tons of cement, consume 58700 tons of desulfurized gypsum, consume 63000 tons of water and consume 40 million degrees of electricity.
(I) Pollutant emission status of cement industry: According to statistics, the annual coal consumption of cement enterprises in the city from January to October 2023 is 1.23 million tons, accounting for 36.1% of the total non-electric coal consumption in the city; Cement production emits 666 tons of particulate matter, 1087 tons of sulfur dioxide and 4086 tons of nitrogen oxides, accounting for 14%, 31% and 51% of the total pollutant emissions of industrial enterprises in the city, respectively.
(II) Construction status of pollution control facilities in cement enterprises: 7 cement enterprises in the city generally have electrostatic dust removal equipment at the kiln head, and the kiln tail adopts electric bag composite dust removal, limestone desulfurization process and "staged combustion + SNCR" denitrification technology, with the denitrification efficiency reaching more than 60%; The emission concentrations of particulate matter, sulfur dioxide and nitrogen oxides are controlled at 20, 100 and 260 mg/m3 respectively according to the Emission Standard of Air Pollutants for Key Industries in Guanzhong Area (DB61/941-2018). At the same time, the kiln head and kiln tail are equipped with on-line monitoring equipment, which is connected with the provincial and municipal ecological environment departments. The 10000-ton line of Jidong Cement Tongchuan Co., Ltd. has been built into a B-level enterprise with stable control of particulate matter, nitrogen oxides and sulfur dioxide within 10 mg/m3, 100 mg/m3 and 50 mg/m3 ; The emission concentrations of particulate matter, nitrogen oxides and sulfur dioxide in the 10,000-ton line of Tongchuan Yaobai Special Cement Co., Ltd. were stably controlled within 5mg/m3, 50 mg/m3 and 35mg/ m3, and passed the provincial evaluation of A-level enterprises. The other five cement enterprises are all C grade. Seven independent cement grinding stations
in the city are equipped with bag-type dust removal equipment to control the particulate matter produced in the production process, and the emission of particulate matter can be stably controlled within 20 mg/m3 as stipulated in the Emission Standard of Air Pollutants for Key Industries in Guanzhong Area, of which Jidong Cement Grinding Branch is a leading enterprise in performance grading. The other six are non-leading enterprises. Fourteen cement enterprises
in the city are equipped with closed greenhouses, spraying dust suppression facilities and vehicle access washing tables, equipped with sprinklers, sweepers and other dust suppression equipment, built with on-line monitoring equipment for dust at the factory boundary, and networked with municipal platforms, which can effectively control dust pollution in the factory area.
2. The main problems
(1) The progress of enterprise performance upgrading is slow. Of the 9 production lines of 7 cement enterprises in the city, only 2 production lines have carried out performance upgrading and creation work, while the remaining 5 production lines have not yet substantially carried out A-level and B-level creation work; The main problem is that the emission index of nitrogen oxides can not meet the requirements of A-level and B-level performance classification of cement clinker industry, and a large amount of funds need to be invested in the implementation of upgrading and treatment projects. However, due to the current downturn in the cement market, the willingness of enterprises to invest and upgrade is not strong.
(2) The management level of grinding stations is not high. The five-year action plan for provincial and municipal air pollution control stipulates that "by the end of 2025, about 60% of independent grinding stations will complete ultra-low emission transformation, and by the end of 2027, all of them will be completed, and cement enterprises that have not completed the transformation within the time limit will not be allowed to produce". At present, only Jidong Cement Grinding Branch in Tongchuan City has reached the ultra-low emission level, and the remaining six independent cement grinding stations have made slow progress in the transformation and treatment of ultra-low emission.
(3) The problem of unorganized emissions from enterprises is relatively common. In the process of raw material transportation, material storage, crushing and transportation, some pollution control facilities still have low collection and treatment rate, and there are phenomena of running, emitting, dripping and leaking; the operation frequency of cleaning vehicles in the factory area is insufficient, the cleaning and sprinkling of the road section is not timely, the washing of the trucks leaving the factory is not in place, and the source control of the vehicle appearance is a mere formality, which is easy to pollute the surrounding environment.
(4) The proportion of clean transportation is not high. The five-year plan of the provincial and municipal air pollution control special action stipulates that the proportion of clean transportation in the cement industry and enterprises with an annual bulk cargo transportation volume of more than 1 million tons should be increased to more than 80%, and that all enterprises involved in bulk material transportation should establish access control systems for units carrying 10 or more vehicles per day; However, only 4 of the 14 cement enterprises in the city have built access control systems, and the proportion of clean transportation in each enterprise generally fails to meet the requirements.
3. Suggestions on
air pollution control in cement industry (1) Accelerate the pace of upgrading enterprise performance. According to the Technical Guidelines for Performance Upgrading of Enterprises in Key Industries of Heavily Polluted Weather issued by the Ministry of Ecology and Environment, we should speed up the performance upgrading of cement enterprises, formulate differentiated emission reduction measures, encourage "advanced" and spur "backward". During the warning period of heavily polluted weather, cement enterprises with advanced environmental performance level should reduce or exempt emergency emission reduction measures; Relying on the existing technical strength, establish a cement industry performance upgrading support expert team, formulate performance upgrading schemes for the support enterprises in turn according to the A-level and B-level enterprise performance standards of the cement industry, and delineate the upgrading roadmap; focus on the weak points, package and plan to declare the provincial air pollution control project funds, so as to reduce the investment pressure of enterprise governance funds; Give full play to the leading role of Jidong Cement and Yaobai Cement in demonstration, and use three to five years to make the proportion of cement enterprises above B level in the whole city reach more than 80%, so as to promote the high-quality development of cement industry in an all-round way.
(2) Strengthen the deep control of enterprise pollution discharge. Strictly implement the Air Pollutant Emission Standards for Key Industries in Guanzhong Area and the Air Pollution Emission Standards for Cement Industry, actively encourage cement enterprises to implement organized and unorganized deep emission control and upgrading projects, guide cement clinker enterprises to formulate ultra-low emission transformation plans, and implement low nitrogen burners, SNCR, SCR, etc. Reduce the emission of particulate matter, sulfur dioxide and nitrogen oxides; guide cement independent grinding station enterprises to strictly control unorganized emissions, give priority to closed, covered or negative pressure operation methods to prevent dust emission, strengthen closed transportation, pavement hardening and cleaning and sprinkling, reduce dust emissions in production links, and comprehensively improve the pollution control level of cement industry.
(3) Improve the management level of enterprise mobile sources. Strengthen the supervision of vehicles entering and leaving enterprises, urge the remaining 10 enterprises to complete the construction of access control and video surveillance system by the end of March 2024, guide enterprises to establish electronic accounts for transport vehicles, and increase the proportion of clean transport in cement enterprises to more than 80%; The existing vehicle washing facilities shall be checked. If the construction standard is low or the washing effect is not achieved, the standard shall be upgraded within a time limit to ensure the standard ton loading, airtight transportation, clean washing and clean appearance of the vehicles leaving the factory, so as to effectively prevent the vehicles from carrying dust on the road. The management of off-road mobile machinery in the factory area shall be strengthened, the vehicle management account shall be established, and the coding registration and exhaust emission detection shall be standardized.
(4) Promoting the high-quality development of the cement industry. Strengthen the training of environmental protection personnel in the cement industry, carry out training around the cement industry regulations and standards system, policy requirements, technical specifications and other systems, to help employees master the relevant policies and regulations of air pollution control in central provinces and cities; Adhering to the principle of "going out, inviting in", inviting experts from the cement industry to hold training seminars in copper, organizing enterprise comrades to go out to learn the management experience of the cement industry in brotherly cities, understanding advanced management technology, absorbing advanced management concepts, from coal consumption indicators, energy consumption indicators, emission indicators, electricity consumption, etc. Efforts should be made to realize the "win-win" between the healthy development of cement industry enterprises and the control of atmospheric environment.
(the writer is deputy director of the Municipal Bureau of ecological environment)
