Green cement: new option for energy saving, China

Green cement: new option for energy saving, China
Published: 20 October 2006

As shown by data provided by Lei Qianzhi, President of China Cement Association, "During the first five months of this year, the cement industry had realised an output of 429Mt, up 20.4 per cent YoY, while the total profits of the industry had increased by 290.4 percent year on year.

Although the prices of both coal and electricity power had surged by a small margin, the growth rate of sales costs for cement is one percentage point lower than that of sales incomes; and the unit energy consumption for cement products had decreased by 4.1 percent on a year-on-year basis."

Nevertheless, "For the moment, the unit energy consumption for China’s cement products is still 43 percent higher than the internationally leading level and the energy consumption of cement production accounts for 7 percent or so of China’s total energy consumption. If conducting a calculation with the 2005 output of 1.06 billion tons, 1.06 million tons of standard coal will be saved each year if the unit energy consumption of cement products decreases by one percentage point. There exist huge potentials for energy saving in the cement industry."

On April 13, 2006, eight ministries or commissions including the National Development and Reform Commission and the Ministry of Construction issued the Circular on Opinions Concerning Accelerating the Restructuring of the Cement Industry and brought forward guidelines and objectives for the restructuring of the cement industry; and one of the objectives is "to make the unit comprehensive energy consumption of cement products decrease by 25 percent".

President Lei Qianzhi admitted that "It is very challenging" to realize such an objective by 2010. Then, how can the goal of "a decrease of 25 percent" be realized?

As introduced by Lei Qianzhi, a fundamental approach for the cement industry to lower its energy consumption is to replace such behind-lagging technology as shaft kiln production with the new dry cement production technology and realize the restructuring of the industry. The new dry cement production technology’s production capacity of cement clinker had increased by 364.63 million tons from 66,56 million tons in 2000 to 431.19 million tons in 2005, and the average annual growth rate is 45.3 percent with an increment of 72.92 million tons. Nevertheless, the shaft kiln production in the Chinese cement industry still accounted for 52 percent by the end of 2005 while the new dry cement production only accounted for 40 percent.


At the same time, the cement industry is accelerating its promotion of using industrial waste residue in the mixture material so as to reduce the consumption of cement clinker by a large margin and lower down the energy consumption. Lei conducted a calculation in the face of the reporter: considering a cement output of 1 billion ton, over 10 million tons of standard coal and over 10 billion kwh electricity could be saved each year if the proportion of industrial waste residue mixed into the cement clinker could be raised from the present 20 percent to 30 percent.