Scholarlink

<p>Tantalum-niobium slags contain high levels of fluorine, particularly in the form of uranium–thorium fluorides. Improper disposal can lead to radioactive environmental hazards. This study investigated the effects of aluminum salt dosage, sulfuric acid concentration, liquid-to-solid ratio, temperature, and leaching time on fluoride release from the slags. Results show that adding aluminum salt promotes fluoride dissolution from uranium–thorium fluorides. However, excess aluminum forms stable fluorine-aluminum complexes, reducing the concentration of free fluoride ions in solution. Kinetic analysis revealed that fluoride release from tantalum slag follows the shrinking core model controlled by internal diffusion. Fluoride release from niobium slag fits a mixed-control model. According to Arrhenius plots, the apparent activation energies were 22.65&#xa0;kJ/mol for tantalum slag and 37.44&#xa0;kJ/mol for niobium slag. Furthermore, valuable cryolite was successfully synthesized from the fluorine-containing leachate using aluminum compounds as precipitating agents. This study provides technical guidance for controlling fluorine migration in industrial solid wastes and suggests a potential pathway for resource recovery.</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

Release behavior of fluoride ions during the leaching of uranium and thorium from Ta–Nb slag with sulfuric acid and aluminum salts

  • 期刊论文

  • 发表日期：

    2026年3月18日

查看全文
  • Junxin Liu,
  • Jiaai Chen,
  • Daqian Liu,
  • Min Huang,
  • Taoyuan Xiu,
  • Zhirong Liu

摘要

Tantalum-niobium slags contain high levels of fluorine, particularly in the form of uranium–thorium fluorides. Improper disposal can lead to radioactive environmental hazards. This study investigated the effects of aluminum salt dosage, sulfuric acid concentration, liquid-to-solid ratio, temperature, and leaching time on fluoride release from the slags. Results show that adding aluminum salt promotes fluoride dissolution from uranium–thorium fluorides. However, excess aluminum forms stable fluorine-aluminum complexes, reducing the concentration of free fluoride ions in solution. Kinetic analysis revealed that fluoride release from tantalum slag follows the shrinking core model controlled by internal diffusion. Fluoride release from niobium slag fits a mixed-control model. According to Arrhenius plots, the apparent activation energies were 22.65 kJ/mol for tantalum slag and 37.44 kJ/mol for niobium slag. Furthermore, valuable cryolite was successfully synthesized from the fluorine-containing leachate using aluminum compounds as precipitating agents. This study provides technical guidance for controlling fluorine migration in industrial solid wastes and suggests a potential pathway for resource recovery.