At present, it is an indisputable fact that the cement industry has a serious overcapacity. So how to resolve the overcapacity? Should we just shut it down? What impact do the cement plants in various places have on the environment? We try to sort out the current pressure, industry technology upgrades and future capacity outlets.

Environmental pressure

The cement production capacity utilization rate is low, but the energy consumption of the cement industry is very high, and the overall pollution situation in the industry is serious.

"China's mainstream 5,000-ton daily production line consumes about 100 kilograms of standard coal and 90 degrees of electricity to produce 1 ton of cement." Zhao Maoxin, a process engineer at China National Materials International Engineering Co., Ltd., said.

It is reported that standard coal, also known as coal equivalent, has a unified calorific value standard. China stipulates that the calorific value of one kilogram of standard coal is 7,000 kcal. Different types and contents of energy are converted into standard coal with a calorific value of 7,000 kcal per kilogram according to their different calorific values.

Cement enterprises are large users of coal. According to general design requirements, the ash content is less than 30%, the sulfur content (bituminous coal) is less than 2%, (anthracite) is less than 5%, and the calorific value is greater than 5,000 kcal. If high-calorie and low-sulfur coal is required, the unit coal price will be high, which has a significant impact on cement costs.

Coal burning has carbon emissions, electricity consumption also has carbon emissions, and during the cement production process, limestone decomposition has carbon emissions. It is conceivable how much carbon dioxide will be emitted during the cement production process.

Theoretical analysis shows that according to the current level of China's cement industry, the production of 1 ton of cement clinker emits about 940 kilograms of carbon dioxide. In China, carbon dioxide emissions from cement production account for about 20% of the total carbon dioxide emissions from industrial production.

Under the heavy pressure of environmental protection, various places are currently taking action. Tangshan City, one of the concentrated areas of cement production, requires all types of coal users to prohibit the use of coal with a sulfur content of more than 0.6% and an ash content of more than 15%. At present, Beijing Jinyu Shunfa Cement Co., Ltd. and Beijing Jinyu Pinggu Cement Co., Ltd. have shut down coal-fired kilns and will stop production by the end of this year, which can reduce cement production capacity by 1.5 million tons, reduce coal consumption by 110,000 tons per year, reduce sulfur dioxide emissions by about 140 tons, reduce nitrogen oxide emissions by about 1,600 tons, and reduce smoke and dust emissions by about 390 tons.

Strategy for resolving overcapacity: suppressing and improving the grade

The "Guiding Opinions on Resolving the Contradiction of Serious Overcapacity" (hereinafter referred to as the "Opinions") issued by the State Council this time reflects the requirement to continuously improve the quality of cement products and gradually eliminate low-grade products, so as to encourage some small companies that lack competitiveness to exit the market.

The Opinion proposes: "Speed up the revision of cement and concrete product standards and related design specifications, promote the use of high-grade cement and high-performance concrete, cancel the 32.5 composite cement product standards as soon as possible, and gradually reduce the proportion of 32.5 composite cement."

Gao Changming, senior consultant of the China Cement Association, once publicly told the media that the current 32.5 composite cement, that is, low-grade cement, accounts for more than 65% of the market, 42.5-grade medium-grade cement accounts for 25%, and 52.5-grade high-grade cement accounts for less than 10%.

The so-called 32.5 composite cement refers to composite cement whose strength value should reach 32.5 according to national standards.

The national standard only clarifies the strength marking, and the composition is not clear, so a lot of admixtures can be added to this type of cement, such as fly ash or limestone, because these materials are only about tens of yuan per ton, which means that the more admixtures, the lower the cost and the greater the profit margin.

"This can also explain why the same bag of cement marked as 32.5 is sold for 30 yuan in some cases and only 20 yuan in others." According to Zhao Maoxin, the main reason why companies produce 32.5 composite cement is to make more money. Most of the composite cement with this grade is produced by some small cement companies, and most of it is sold to retail customers in the market. Some large-scale construction projects have higher requirements for cement and stricter audits, so they often do not choose this product.

Kong Xiangzhong, executive vice president and secretary general of the China Cement Association, pointed out that since the clinker strength produced by the new dry process cement production line is generally higher, the amount of admixture added to the composite cement with a strength of 32.5 is also higher. In actual production, in order to reduce production costs, some companies, especially small grinding stations, use a large amount of industrial waste in the varieties of admixtures, many of which exceed the range specified by national standards, which poses a hidden danger to the quality of cement products.

Kong Xiangzhong said, "The cancellation of 32.5 composite cement varieties as soon as possible is not only beneficial to ensuring cement quality, but also accelerates the elimination of backward small grinding stations, which is beneficial to the adjustment of industry structure, environmental protection, and also plays a role in resolving cement overcapacity."

Chen Guoqing, vice president of the China Building Materials Federation, believes that it is necessary to accelerate the research and development of "second-generation new dry process cement technology and equipment", which includes "new low-carbon high-grade cement clinker production technology", which will be beneficial to the production of high-grade cement.

According to the "2013 First Half Cement Industry Economic Operation Report" released by the China Cement Association, China's cement clinker production capacity increased by 4.15% year-on-year in the first half of this year, lower than the 9.67% increase in cement production. The China Cement Association believes that this shows that China's low-grade product market is still on the rise, and product structure problems are still prominent.

According to Wang Wei, chairman of Sinoma International, the clinker blending ratio of China's cement was about 59% last year, which is significantly lower than the level of more than 80% in European countries. According to Wang Wei's calculation, if the cement clinker ratio is increased to 75%, China's cement production capacity will drop to about 2.3 billion tons. Compared with China's cement consumption of 2.2 billion tons last year, there is still room for improvement.

A new way to resolve capacity: handling hazardous waste

Newly launched cement companies now basically need to deal with urban garbage, industrial waste and other treatments, otherwise it will be difficult to apply successfully. Zhao Maoxin said, "In dealing with garbage and tailings, the cement industry actually undertakes most of the city's environmental protection tasks."

"The kiln that burns cement is recognized in the world as the industrial kiln with the safest treatment process and the most thorough treatment results. Cement plants in developed Western countries also assume the function of ultimately absorbing various pollutants in their cities." Kong Xiangzhong, executive vice president and secretary general of the China Cement Association, said.

"Take Japan as an example. There are many cement plants, and the cost of producing cement is not high. A large part of the contribution of these enterprises is to deal with hazardous waste." Kong Xiangzhong introduced, "They deal with garbage, waste tires, and plastic products, and then get subsidies from the government, which makes the cost very low. The waste tires in developed countries around the world are finally disposed of by cement plants."

In China, the case of cement plants contributing to environmental protection has long become a reality.

In the "Beijing Clean Air Action Plan 2013-2017" released recently, Jinyu Group is responsible for reducing cement production. According to the plan, the cement production capacity will be reduced to 6 million tons in 2015, and the city's cement production capacity will be further reduced to about 4 million tons in 2017. The retained capacity will be used for the coordinated disposal of hazardous waste.

Jinyu Group independently developed and utilized the core technology of cement kiln to coordinate the disposal of urban waste. All cement enterprises in Beijing have the function of "digesting" industrial waste and urban domestic waste. It is understood that the scope of waste disposal by Jinyu Group using cement kilns has covered sludge, domestic waste and 30 of the 49 categories in the national hazardous waste list.

Take Beijing Cement Plant as an example, it handles 100,000 tons of white hazardous waste every year, including waste materials from pharmaceutical factories, medical waste, and waste ink and waste banknotes from printing and dyeing factories. (CCTV.com reporter Bao Zhengyu comprehensive report)

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