Thermal power coal dust utilization is a large "article"

In early January 2012, the National Development and Reform Commission printed and issued the “Twelve Five-Year Plan” Guidelines for Comprehensive Utilization of Resources and the “Implementation Plan for Comprehensive Utilization of Bulk Solid Wastes,” which states that “by 2015, a batch of fly ash high- Value, large amount of comprehensive utilization of bases, supporting a group of professional use of backbone enterprises, the new 60 million tons of annual waste capacity, comprehensive utilization of fly ash increased to 70%.

Fly ash, commonly known as coal ash. Mainly due to the solid waste (non-combustible particulate matter, dusty) remaining after coal-fired power plants, which contain a lot of aluminum oxide, silicon dioxide and cadmium, chromium, mercury, lead and other heavy metals. At present, it is one of the major industrial wastes in China. In the general trend of the thermal power industry to seek a green transformation, the unfamiliar word of fly ash has begun to enter the people's field of vision.

Coal dust pollution, need to pay more attention to

According to the estimation of Greenpeace, as of 2009, the output of fly ash in China has reached 375 million tons, which is equivalent to more than double the total amount of domestic garbage in China. If these fly ash is not properly treated, it will not only cause environmental pollution, but also endanger the health of the body.

At the beginning of this century, China entered a period of great leaps in thermal power installations, and the number of coal dust produced each year is continuously rising. Although there are "Environmental Protection of Solid Waste Pollution Prevention" (revised in 2004); 2009, "Guidelines on Strengthening the Prevention and Control of Heavy Metal Pollution" and other related laws and regulations. However, in general, there are still many problems in the recycling of pulverized coal ash, as well as in prevention measures such as site selection, anti-distribution, anti-leakage, and anti-drainage. According to the reporter's knowledge, at present, many places in China deal with pulverized coal ash by simple methods of discharge and stacking. In addition, preventive measures are not in place. In the event of rain or windy weather, there will be escape or leakage, such as entering the atmosphere or drinking or farming. Water can cause great harm.

In 2011, there were a number of heavy metal pollution incidents in China. Although not directly related to the pulverized coal ash in thermal power plants, the potential for pollution and damage as a pulverized coal ash containing a large number of heavy metal elements cannot be ignored. Vice Premier Li Keqiang said at the Seventh National Environmental Protection Conference: "We must strictly implement the comprehensive prevention and control plan for heavy metal pollution and effectively reduce the harm caused by heavy metal pollution. First, we must rationally adjust the layout of enterprises involved in heavy metals, strictly implement the health protection distance, and concentrate on the population. The district and the drinking water and food safety guarantee zones are firmly forbidden to new projects.The second is to improve the barriers to entry, supervise the enterprises in order to ensure stable discharge of standards, and enterprises that fail to meet the standard shall stop production until the closure of the company. The project measures will be intensively treated to expedite the resolution of historical issues such as chromium slag and tailings ponds."

Turn waste into treasure, promote the development of thermal power cycle

"There is no useless garbage, only misplaced resources," especially for coal-fired power plants. The extraction of aluminum-silicon alloys and their use in the manufacture of cement are the main ways to use pulverized coal ash in the future. The former can be used instead of aluminum, silicon raw materials, aluminum-silicon alloy manufacturing; the latter can help improve the performance of cement.

At present, some regions in China are already advancing this cyclical development model. It has been reported that the investment in Zhuozhou, Shanxi, is 3.348 billion yuan for the construction of six projects, and its annual use of fly ash can reach 2.42 million tons. At the end of 2011, the unveiling of the mineral resource comprehensive utilization demonstration base of the Shenhua Zhungeer mining area and the 1 million tons of alumina production demonstration plant for the first phase of the coal associated resource recycling economy project of the Shenhua Zhungeer mining area were started. The deputy general manager of Shenhua Group, China Shenhua Energy Ling Wen, president of the stock company, said that this project will “remove alumina and * from fly ash from circulating fluidized bed power plants, and conduct production and processing of related products. This can alleviate the current severe shortage of aluminum resources in China, and The country's circular economy industry, energy saving and emission reduction work is a major **, with great practical significance and historical significance."

These will only be the prelude to the promotion of circular economy during the "Twelfth Five-Year Plan" period in China. In the "Twelve Five-Year Plan for Comprehensive Utilization of Resources" issued recently and "Implementation Plan for Comprehensive Utilization of Bulk Solid Waste," a comparative review was made on how to recycle various solid wastes including coal dust. Detailed planning, and proposed to build a number of fly ash high value-added, large-volume comprehensive utilization base.

Turn waste into treasure, still need to work hard in many ways

The recycling of pulverized coal ash not only has economic value but also has social value. During the "12th Five-Year Plan" period, this recycling model will be continuously promoted and implemented. At the same time, experts also stated that at present, China still has problems in the reuse of pulverized coal ash, mainly reflected in three aspects: First, the level of technology, comprehensive utilization of pulverized coal ash is a technically demanding project. China's current level of technology in this area has yet to be improved; the second is economic issues. On the whole, China has a high cost in the comprehensive utilization of resources. On the one hand, the amount of funds required for project investment is high, and on the other hand, the transportation costs are high. Third, policy constraints are not strong and support is insufficient. Of the related 20 or more industry standards, most of them do not have mandatory requirements, and the corresponding supervision work is often not very effective. It is difficult to effectively implement the current situation where the thermal power industry is generally weak. In addition, the state needs to further improve its support for relevant taxes and incentives.

Some experts also pointed out that achieving the goal of effective recycling of pulverized coal ash can not be accomplished overnight. In the process of advancing step by step, it is necessary to do a good job in the treatment of coal dust pollution that has emerged, and how to effectively prevent the emergence of new ones. pollution problem. (Guo Liqi)

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The relevant contents of the "Twelve Five-Year Plan for Comprehensive Utilization of Resources" and "Implementation Plan for Comprehensive Utilization of Bulk Solid Wastes":

1. By 2015, the total recovery rate of mineral resources and the comprehensive utilization rate of co-produced minerals will increase to 40% and 45%; the comprehensive utilization rate of bulk solid waste will reach 50%, of which the comprehensive utilization rate of industrial solid waste will reach 72%, and the comprehensive utilization of crop straw The rate strives for more than 80%; the recovery and utilization rate of major renewable resources is increased to 70%, of which recycled copper, aluminum and lead account for 40%, 30% and 70% of the total output of the year.

2. Focusing on the large-scale utilization and efficient use of wastes with large emissions, large stocks, and high potential for resources, breakthroughs have been made to build renewable resource recovery systems and improve the overall level of industries, including the comprehensive development of co-associated minerals. Utilization, traditional focus areas of comprehensive utilization of industrial waste, and 31 key areas with certain forward-looking emerging fields such as recycling of marine waste and waste textiles.

3. Comprehensive utilization of key resources, such as coal, power, petroleum, petrochemical, steel, non-ferrous metals, chemicals, building materials, and light industry, shall be selected by key enterprises with high utilization, high output value, advanced technical equipment, and leading demonstration role. Nurture.

4. Build a batch of coal gangue production chemical products and new building materials demonstration bases, coal gangue filling downhole demonstration projects, add 90 million tons of annual profit and waste capacity, increase the comprehensive utilization ratio of coal gangue to 75%, and build a batch of fly ash Added value, large-volume comprehensive utilization base, support for a group of professional use of backbone enterprises, new annual capacity of 60 million tons of waste, fly ash comprehensive utilization increased to 70%.