Relevant officials from the Ministry of Industry and Information Technology expressed that during the 12th Five-Year Plan period, through pilot demonstration, cement enterprises around cities which have conditions will be guided to orderly turn into urban purifiers. The cement industry will be developed into a functional industry that combines cement production with harmless disposal of waste.
In the Outline of the Twelfth Five-Year Plan for National Economic and Social Development, supporting the construction of cement kilns for co-processing urban household garbage and sludge production lines and comprehensive utilization demonstration lines for construction waste is one of the key points of building materials industry development. Utilizing cement kilns for harmless ultimate co-disposal of urban garbage (including domestic garbage, sludge and various toxic and hazardous wastes), turning cement rotary kilns into purifiers, is an important way to develop a circular economy and build ecological harmony, and also a new mission that the cement industry will undertake.
Currently, with the acceleration of China's industrialization and urbanization construction process, dealing with a large amount of urban domestic garbage has become a major issue facing many cities. According to statistics, the stock of garbage in China has reached 6 billion tons, occupying 750,000 mu of farmland, and every year, another 200 million tons of urban domestic garbage are newly generated. Achieving urban garbage reduction, resource utilization, and harmless treatment as soon as possible has become an urgent task for cities to achieve harmonious development.
During this year's two sessions, Guo WenSan, a national people's representative and chairman of Anhui Conch Group Co., Ltd., submitted a proposal titled "Suggestions on Promoting the Use of Cement Kiln Co-Processing Urban Domestic Garbage Technology." He said that if a part of the more than 1,100 new dry-process cement production lines spread across the country could be well utilized, it would solve the problem of garbage disposal in urban development relatively well; however, currently, cement kiln co-processing of domestic garbage is still in the technical research category in national policies, and has not received policy support like garbage incineration power generation. Not only is it difficult to widely promote in the market, but issues such as investment, operating costs, and equipment technology upgrades still need to be resolved.
This technology does not require garbage classification, especially suitable for the current situation in China where garbage is generally not classified for collection and has too low calorific value; the heat energy produced by burning garbage can replace part of the fuel used in cement production, and the residue can be used as cement raw material. Compared with traditional garbage disposal methods such as landfilling, composting, and incineration, this technology enables garbage disposal to achieve reduction, resource utilization, and harmlessness. It not only has good energy-saving and emission-reduction effects but also thoroughly solves the problem of urban garbage landfill occupying a large amount of land and polluting the environment, with very obvious social benefits. In January this year, Conch Group signed a cooperation agreement with Guiding County in Guizhou Province to construct a cement kiln garbage processing system. After the project is completed, it will be able to handle all the domestic garbage in Qiannan Prefecture, effectively solving the garbage processing and environmental protection problems in scenic areas.
In China, Anhui Conch Group Co., Ltd. was the first to make attempts. They developed a proprietary technology system for utilizing new dry-process cement kilns to process urban domestic garbage. In March 2010, they built a demonstration project at Tongling Conch Company that processes 600 tons of garbage per day. This project can process about 200,000 tons of urban domestic garbage annually, save up to 13,000 tons of standard coal, and reduce carbon dioxide emissions by about 30,000 tons. Currently, all systems of the project are running normally. By the end of June this year, the garbage processing volume has reached 103,000 tons, and after testing, all environmental protection indicators are fully qualified. Among them, according to sampling by national authoritative institutions and testing by the German Eurofins Analytical Laboratory, the dioxin emission index is only 0.0376 nanograms per cubic meter, much better than the 0.1 nanograms per cubic meter standard required by developed European countries.
Experts pointed out that the cement industry is a resource-based industry, also the industry with the greatest potential for energy saving and emission reduction, and the most capable of consuming various industrial solid wastes. It is one of the industries with the best prospects for developing a circular economy and plays a role that cannot be replaced by other industries.
According to monitoring by the Environmental Protection Agencies of the United States and Germany, using hazardous waste as raw material and fuel in cement rotary kilns not only poses no environmental hazards but is also listed as the best existing demonstration technology. In Japan, cement kilns are already capable of handling various hazardous wastes, including domestic sludge.
In fact, developed countries began using cement kilns to process hazardous waste as early as the 1970s. Taking the United States as an example, dozens of cement plants use hazardous waste as alternative raw materials and fuels, burning them in cement kilns, with substitution rates generally ranging from 20% to 60%; in Europe, the substitution rate of some cement plants has reached over 80%. South Korea, Brazil, and Mexico also have quite high proportions of using cement rotary kilns to process urban garbage waste. In Indonesia, Thailand, Morocco, Pakistan, India, and others, there are also a considerable number of cement plants in operation that handle various hazardous wastes.
In most people's impressions, cement plants emit thick smoke and dust everywhere, aren't they a major source of pollution? How can they be associated with health and safety?
The 2011 China International Cement Summit held recently in Beijing attracted widespread attention because its theme was very special: co-processing, health, and safety. Experts attending the summit discussed in depth how the cement industry can utilize the advantages of cement kilns to achieve harmless ultimate co-disposal of urban domestic garbage and waste, undertaking new social responsibilities and missions to realize harmonious coexistence between humans and nature and coordinated economic and social development.