In recent years, the advantages of highly matching the process characteristics of cement kilns with the demand for hazardous waste disposal have been gradually known by more and more people. However, the accompanying doubts and debates continue. At the
two sessions this year, the proposal of environmental protection enterprise groups "Proposal on Ensuring the Healthy Development of Hazardous Waste Disposal Industry" pointed out a series of problems, such as the limitations, high risks and interference with the healthy development of the market.
Recently, the reporter visited several cement plants in Hebei Province to understand some of the problems in the co-disposal of hazardous wastes in cement kilns.
The incineration removal rate is greater than 99.
It is understood that only the new dry process cement kiln with a single-line design clinker production scale of not less than 2000 tons per day is qualified to co-process solid waste (including hazardous waste).
According to the requirements of the Control Standard for Solid Waste Pollutants Co-disposed in Cement Kilns (hereinafter referred to as the Control Standard) issued by the Ministry of Ecology and Environment, The incineration removal rate of organic markers measured by cement kilns for co-disposal of hazardous wastes should not be less than 99.
Xiao Ying, an expert from China Building Materials Research Institute, told our reporter: "The temperature of cement kilns is relatively high, the temperature of materials in kilns can reach 1450 degrees Celsius, and the temperature of flue gas in kilns may be a little higher." Moreover, the flue gas stays in the kiln for a long time, and the high temperature environment can ensure that the organic matter in the waste can be completely incinerated, which has been tested experimentally when we formulated the Control Standard. In addition, the cement kiln is an alkaline environment, the new dry process makes the flue gas and materials have full contact, but also can effectively avoid the volatilization of acidic substances and some heavy metals.
In addition, the Ministry of Ecology and Environment has formulated the Technical Specification for Environmental Protection of Solid Waste Co-disposal in Cement Kilns (hereinafter referred to as the Technical Specification for Environmental Protection), which also specifies in detail the disposal facilities, the characteristics of solid waste co-disposal in kilns, the technical requirements for operation, the emission limits of pollutants, and the detection of various pollutants. Cement kilns approved for co-disposal of hazardous wastes must meet the requirements of the Control Standards and Technical Specifications.
"That is to say, for cement kilns that do not have the ability to coordinate the disposal of hazardous wastes, the environmental department will not issue hazardous waste disposal permits to cement kilns." Xiao Ying said.
According to the Technical Specification, Laishui Jinyu Jidong Environmental Protection Technology Co., Ltd. (Laishui Environmental Protection Co., Ltd.), which has a 4000 tons/day cement clinker production line, has built a 90 tons/day cement kiln co-disposal hazardous waste demonstration line, which not only undertakes the hazardous waste disposal task of Baoding City and its surrounding waste production enterprises, but also meets the requirements. It also undertakes the government's emergency projects, such as the treatment of Tanghe Sewage Reservoir in Xiongan New District and the harmless disposal of illegal dumping of hazardous wastes in Qingxian County, which provides a strong guarantee for local environmental pollution control. Since the project was completed and put into operation in 2018, the demonstration line has disposed of more than 90000 tons of hazardous waste and reduced the landfill land by more than 10000 square meters.
The According to the actual production capacity , on the basis of not affecting the quality of cement, the reporter learned that 20 of the 21 cement enterprises in Jinyu Jidong in Hebei have carried out the business of co-disposal of solid waste, of which 7 are cement enterprises that dispose of hazardous waste. The disposal capacity is 174,000 tons/year. In 2022, the disposal amount of hazardous wastes is 3. The problem is that hazardous wastes entering the kiln often contain heavy metals and harmful elements such as chlorine, fluorine and sulfur, and some wastes will have dioxins attached to them. Therefore, many people worry that the disposal of hazardous wastes in cement kilns will affect the quality of cement and lead to the leaching of heavy metals in cement. In fact, cement kilns do have the disadvantage of being unable to co-dispose of hazardous wastes containing radioactive, mercury and other heavy metals, which is easy to cause environmental risks. However, the Technical Specification for Environmental Protection has stipulated that such hazardous wastes are prohibited from co-disposal in cement kilns. At the same time, the Technical Specification for Environmental Protection also stipulates the corresponding limits for the content of heavy metals in the co-disposal of hazardous wastes in cement kilns, so as to ensure that the normal production of cement and the quality of clinker meet the national standards, and to avoid environmental risks such as excessive heavy metals. For example, the co-disposal of hazardous wastes in cement kilns requires that the chlorine content in the material kilns should not be greater than 0.04%, the fluorine content should not be greater than 0.5%, and the total content of sulfate and organic sulfur should not be greater than 0. And then incinerated. Mr. Qi, a person in charge of the Energy and Environmental Protection Department of Laishui Environmental Protection Company, told our reporter, "The hazardous waste added in clinker calcination is also added in proportion strictly according to the corresponding national standards." According to reports, at present, the maximum amount of solid waste co-disposed by one ton of cement is 15% of cement clinker. "Even if the amount of hazardous waste contained in these solid wastes is very low, it can not exceed this amount, and the specific amount of mixing should be calculated according to the total amount of harmful ingredients in raw materials." Mr. Qi said, "For example, if we produce 4000 tons of cement clinker a day, we can't add more than 600 tons of solid waste a day." Reporters noted that the "Technical Specification for Co-disposal of Solid Waste in Cement Kilns" issued by the General Administration of Quality Supervision, Inspection and Quarantine (hereinafter referred to as "Technical Specification") also put forward limits for heavy metal content in cement clinker, and the cement produced by cement kilns for co-disposal of hazardous wastes should not only conform to the national standard "General Portland Cement". It shall also comply with the requirements of the Technical Specification. Xiao Ying said: "The state has issued a series of standards and norms, which have made detailed regulations and restrictions on the co-disposal of solid waste in the whole cement kiln, restricting the types and disposal processes of hazardous waste in the cement kiln and ensuring the quality of cement products.". Therefore, in fact, the problem that the disposal of hazardous wastes in cement kilns affects the quality of cement has been technically controlled and solved. Therefore, in recent years, the co-disposal of cement kilns has gradually developed and become an effective supplement to the harmless and resource utilization of hazardous wastes. Co-disposal of hazardous wastes suitable for disposal can not completely replace traditional hazardous waste incineration projects . Throughout the industrial field, the cement industry is the most suitable industry for co-disposal of hazardous wastes. In Europe, the United States, Japan and other developed countries and regions, cement kilns were used for co-disposal of solid wastes (including hazardous wastes) in the 1970s. After more than 40 years of development, cement kiln co-disposal technology has developed into a mature technology widely used in developed countries and regions, which has played an important role in the sustainable development of the cement industry and solid waste disposal. Since 1990, China began to practice the co-disposal technology of cement kilns, and in the past 20 years, relevant policies have been issued to encourage and support the co-disposal of solid waste in cement kilns. At present, there are about 70 enterprises with the qualification of co-disposal of hazardous wastes in cement kilns in China, covering more than 20 provinces and cities. Under the background of "double carbon", co-disposal of cement kilns has become an important profit point for the transformation and upgrading of the cement industry. Therefore, many people point out that the co-disposal of hazardous waste in cement kilns will impact the professional hazardous waste market and even replace hazardous waste enterprises. The reason for this concern is that in cement kilns, waste can also partially replace the raw materials and fuels used in cement production, and its production process has the advantage of harmless to resource utilization of hazardous waste. Moreover, the cement kiln co-processing project is based on the transformation of the original cement kiln, the construction period is short, and the investment and operation costs are lower than those of professional hazardous waste disposal enterprises. Therefore, cement enterprises can make contributions in the field of hazardous waste disposal with the absolute advantage of low price, forming a pattern of mutual love and killing with some traditional hazardous waste enterprises. It is noteworthy that recently, the National Development and Reform Commission issued the List of Operating Service Charges Priced by the Government (2023 Edition), in which some major provinces have adjusted the pricing of hazardous waste disposal fees, and different regions have given guidance prices for different hazardous waste disposal, so as to avoid the price of hazardous waste disposal being too high or too low. Industry insiders have analyzed that in the fierce competition in the hazardous waste market, there are not only cement plants, but also the blind expansion of the old hazardous waste enterprises, the entry of environmental protection and water giant enterprises, the cross-border of external forces such as real estate, and many scattered small players from all sides, although there are many participants, but they are generally small in scale. The market share of the top ten enterprises in the industry is less than 10%, and the companies that can handle more than 25 kinds of hazardous wastes only account for about 1% of the total number of the country. Ultimately, how the industry develops will be affected by market rules. It is worth mentioning that not all hazardous wastes are suitable for disposal in cement kilns. At present, the types of hazardous wastes that can be disposed of in cement kilns account for about 60%. According to Qiao Yonghong of the Party and Mass Discipline Inspection Department of BBMG Jidong Cement Baoding Area, "The approved disposal scope of the hazardous waste co-disposal project of cement kilns in Baoding Area only covers eight categories and 64 sub-categories." In Xiao Ying's opinion: "Cement kiln co-disposal of hazardous waste has unique advantages, but it can not completely replace the traditional hazardous waste incineration project. The waste suitable for cement kiln co-disposal should meet the basic characteristics of raw materials or fuels for cement production, and should not adversely affect the cement production process, cement product quality and environmental safety."." On July 6-7, 2023, China Cement Network will hold the" 2023 China Cement Energy Conservation and New Energy Development Conference " in Chongqing. CNBM , Conch Group, BBMG Jidong, Hongshi Group, Huaxin Cement, China Resources Cement, Taiwan Cement, Shanshui Group, < a href = "https://price.ccement.com/brandnewslist-1-1000162.".
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