Scholarlink

<p>Secondary aluminum ash was modified with malic acid to prepare the adsorbent for a fluoride absorption. The effects of contact time, adsorbent dose, and pH on the defluorination effect of adsorbent were investigated. The structure and properties of the adsorbent were characterized by SEM, EDS, N<sub>2</sub> adsorption–desorption isotherm, XRD, FTIR, TEM, XPS, and removal rate. The results show that the surface roughness of the secondary aluminum ash modified by sintering and malic acid gradually increased. The BET specific surface area and pore volumes of secondary aluminum ash modified by sintering and malic acid were 42.691 m<sup>2</sup>/g and 0.128 cm<sup>3</sup>/g, respectively. The peak strength of F in the secondary aluminum ash was enhanced after adsorption, and the main phase in the ash was γ-Al<sub>2</sub>O<sub>3</sub>. The –OH peak of the modified secondary aluminum ash was enhanced and the –OH peak strength was weakened after adsorption of fluoride. The spacing between the interplanar distance of the adsorbent material was 0.24&#xa0;nm. The fluoride adhered to the secondary aluminum ash surface by mainly substituting the hydroxyl group (–OH) on the surface of the adsorbent and forming an Al-F complex. When pH&#xa0;=&#xa0;2, the maximum adsorption capacity was 92.8&#xa0;mg/g. The adsorption process accorded to the pseudo-second-order kinetic model, the correlation coefficient, <i>R</i><sup>2</sup>&#xa0;=&#xa0;0.9995, indicating that the defluorination was chemisorption. The adsorption mechanism is mainly ion exchange and the formation of complexes. The liquidus temperature of the fluoride-containing Al<sub>2</sub>O<sub>3</sub> industrial electrolyte system was 913&#xa0;°C. The Al<sub>2</sub>O<sub>3</sub> solubility in fluoride-containing Al<sub>2</sub>O<sub>3</sub> electrolyte increased by 0.9 wt% compared to traditional aluminum industry electrolytes.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Removal of Fluoride from Aluminum Industrial Wastewater by Secondary Aluminum Ash for the Preparation of Fluoride-Containing Al2O3 for Low-Temperature Aluminum Electrolytes

  • 期刊论文

  • 发表日期：

    2025年9月15日

查看全文
  • Haitao Liu,
  • Hui Fang,
  • Jie Li,
  • Zhenhua Yang,
  • Jianhua Liu,
  • Ziming Huang,
  • Daqing Xing

摘要

Secondary aluminum ash was modified with malic acid to prepare the adsorbent for a fluoride absorption. The effects of contact time, adsorbent dose, and pH on the defluorination effect of adsorbent were investigated. The structure and properties of the adsorbent were characterized by SEM, EDS, N2 adsorption–desorption isotherm, XRD, FTIR, TEM, XPS, and removal rate. The results show that the surface roughness of the secondary aluminum ash modified by sintering and malic acid gradually increased. The BET specific surface area and pore volumes of secondary aluminum ash modified by sintering and malic acid were 42.691 m2/g and 0.128 cm3/g, respectively. The peak strength of F in the secondary aluminum ash was enhanced after adsorption, and the main phase in the ash was γ-Al2O3. The –OH peak of the modified secondary aluminum ash was enhanced and the –OH peak strength was weakened after adsorption of fluoride. The spacing between the interplanar distance of the adsorbent material was 0.24 nm. The fluoride adhered to the secondary aluminum ash surface by mainly substituting the hydroxyl group (–OH) on the surface of the adsorbent and forming an Al-F complex. When pH = 2, the maximum adsorption capacity was 92.8 mg/g. The adsorption process accorded to the pseudo-second-order kinetic model, the correlation coefficient, R2 = 0.9995, indicating that the defluorination was chemisorption. The adsorption mechanism is mainly ion exchange and the formation of complexes. The liquidus temperature of the fluoride-containing Al2O3 industrial electrolyte system was 913 °C. The Al2O3 solubility in fluoride-containing Al2O3 electrolyte increased by 0.9 wt% compared to traditional aluminum industry electrolytes.