Thermal behaviors of fluorine during (co-)incinerations of spent potlining and red mud: Transformation, retention, leaching and thermodynamic modeling analyses
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Dosyalar
Tarih
2020
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Pergamon-Elsevier Science Ltd
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Spent potlining (SPL) as a hazardous solid waste has a high content of inorganic fluorine. This study aimed at characterizing its transformation, retention and leaching behaviors with(out) the addition of red mud (RM) during the SPL incineration. The RM addition positively affected its retention and leaching rates. Its Ca-containing compounds caused Na3AlF6 and NaF to turn into more CaF2. 30% RM converted water-soluble NaF into more stable CaF2 than did SPL at 850 degrees C, thus reducing the leaching rate by 45.15%. 30% RM captured HF through its Ca content and enhanced its retention rate by 66.96%. 66.01% of the total fluorine was stably retained in the bottom ash, and thus, significantly reduced the toxicity of the SPL incineration products. SiO2 and Al2O3 exerted a thermally positive effect on NaF turning into CaF2. The fluoride retention of the bottom ash was mainly dominated by CaF2 and NaF with(out) RM. Smaller, coarser and more loose structures of the co-incinerated solid particles pointed to a synergistic interaction between SPL and RM. (C) 2020 Elsevier Ltd. All rights reserved.
Açıklama
Anahtar Kelimeler
Spent Potlining, Red Mud, Fluorine, Retention, Leaching, Mineral Transformation
Kaynak
Chemosphere
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
249
