Recycling ash into the first stage of cyclone pre-heater of cement kiln

• Ming-Xiu Zhan ^[1] ; Jian-Ying Fu ^[3] ; Jouni Havukainen ^[2] ; Tong Chen ^[1] ; Xiao-Dong Li ^[1] ; Jian-Hua Yan ^[1] ; Alfons Buekens ^[1]
  1. [1] Zhejiang University

     Zhejiang University

     China

     
  2. [2] Lappeenranta University of Technology

     Lappeenranta University of Technology

     Lappeenranta, Finlandia

     
  3. [3] China United Engineering Corporation

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• Localización: Waste management, ISSN-e 0956-053X, Vol. 56, 2016, págs. 229-237
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • Fly ash collected from the bag filter could be recycled into the first stage of the cyclone pre-heater of the cement kiln, resulting in the possible enrichment of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). In this study, soxhlet fly ash (SFA) and raw meal (RM) were selected as the basis for the PCDD/F formation experiments. The levels of 2,3,7,8-PCDD/Fs formed on the SFA and RM were observed to be 2550 pg/g (157 pg I-TEQ/g) and 1142 pg/g (55 pg I-TEQ/g), respectively. While less 2,3,7,8-PCDD/Fs was detected when SFA was mixed with RM, suggesting that recycling cement kiln ash would not largely increase the concentration of PCDD/Fs in flue gas. Furthermore, the possible influencing factors on the PCDD/F formation were also investigated. The formation of 2,3,7,8-PCDD/Fs was up to 10,871 pg/g (380 pg I-TEQ/g) with the adding of CuCl2, which was much higher than the results of CuO and activated carbon. Most importantly, the homologue, congener and gas/particle distribution of PCDD/Fs indicated that de novo synthesis was the dominant PCDD/F formation pathway for SFA. Lastly, principal component analysis (PCA) was also conducted to identify the relationship between the compositions of reactant and the properties of PCDD/Fs produced.