Inorganic Chemicals Industry ›› 2024, Vol. 56 ›› Issue (6): 109-118.doi: 10.19964/j.issn.1006-4990.2023-0459

• Environment·Health·Safety • Previous Articles     Next Articles

Study on defluorination process of secondary aluminum ash wet process and conversion behavior of fluoride

XU Zijian1(), WANG Yu2, LIU Jingyong1(), ZHU Chuanghai1, CHEN Zhibin1, HUANG Shengzheng1, XIE Wuming1, SUN Shuiyu1   

  1. 1.School of Environmental Science and Engineering,Guangdong University of Technology,Guangzhou 510006,China
    2.State Key Laboratory of Solid Waste Reuse for Building Materials,Beijing Building Materials Academy of Sciences Research,Beijing 100041,China
  • Received:2023-09-19 Online:2024-06-10 Published:2024-06-20
  • Contact: LIU Jingyong E-mail:1030280592@qq.com;Liujy@gdut.edu.cn

Abstract:

In order to study the influence of wet defluorination factors(liquid-solid ratio,time,temperature,solution type and solution concentration) on the fluoride leaching efficiency and the fluoride leaching of the bottom slag during the wet treatment of secondary aluminum ash,a single factor experiment was used to determine the fluoride content of the bottom slag and its leaching solution before and after wet leaching.At the same time,XRD and SEM-EDS were used to characterize the original aluminum ash and the bottom slag after wet treatment.The results showed that the above five factors affected the fluoride leaching efficiency under the two leaching media conditions.Under the condition of constant temperature and wet leaching,the fluoride removal effect of NaOH solution was better than that of deionized water.The optimal parameters of deionized water leaching fluoride were as follows:ratio of liquid to solid(mL/g)of 30,hydrolysis time of 4 h,hydrolysis temperature of 90 ℃,and leaching rate of fluoride of 12.98%.Under normal temperature conditions,the optimal parameters were as follows:ratio of liquid to solid(mL/g)of 10,concentration of NaOH solution of 1.5 mol/L,hydrolysis time of 30 min,and leaching rate of fluoride of 65.85%.XRD results showed that the content of AlN in the secondary aluminum ash was reduced to different degrees after wet treatment,and SEM-EDS results showed that the content of fluoride in the bottom slag was reduced correspondingly after wet treatment.The above research results provided a scientific basis for the removal of fluoride in the wet treatment of secondary aluminum ash.

Key words: secondary aluminum ash, wet hydrolysis, fluoride, alkali leaching defluorination

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