6A. Zabaniotou, C. Theofilou. Green energy at cement kiln in Cyprus-Use of sewage sludge as a conventional fuel substitute [J]. Renewable & Sustainable Energy Reviews, 2008, 12: 531-541.
7Kae-Long Lin, Chung-Yi Lin. Hydration characteristics of waste sludge ash utilized as cement raw material[J]. Cement and Concrete Research, 2005, 35: 1999--2005.
8Pai Haung Shih, Juu-En Chang, Hsing-Cheng Lu, Li-Choung Chiang. Reuse of heavy metal containing sludges in cement production[J]. Cement and Concrete Reaearch, 2005, 35: 2110-2115.
9P. G., Ract, D. C. R. Espinosa, J. A. S. Tenorio. Determination of Cu and Ni incorporation ratios in Portland cement clinker[J]. Waste Management, 2003, 23 : 281- 285.
10K. Kolovos, S. Tsivilis, G. Kakali. The effect of foreign ions on the reactivity of the CaO-SiO2-Al2O3 Fe2O3 system: part II, cations[J]. Cement and Concrete Research, 2002, 32 (3) : 463-469.