ABSTRACT

The current fluorine wastewater treatment method mainly relies on neutralization, which has the drawback of high alkali consumption, solid waste generation, and re-dissolution of heavy metals. Similar problems exist in the vanadium (V) industry. This study aims to minimize fluorine wastewater generation, reducing CaF₂ consumption by internally reusing raffinate at certain stages of the V extraction process. In the raffinate reuse leaching process, Al-F complex in the raffinate is decomposed and HF is produced under the action of sulfuric acid. This enhances the destruction of muscovite and improves the leaching efficiency of V. Response surface methodology (RSM) was used to optimize the raffinate reuse leaching process, and when the CaF₂ dosage was reduced from 3 wt.% to 1.8 wt.% and the H₂SO₄ concentration was as low as 14 vol%, the process maintained the optimal V recovery efficiency of more than 86%. This methodology can achieve a 100% reuse rate of the raffinate, and has great potential for its application in the vanadium leaching industry.

摘要

目前的含氟废水处理方法主要依靠中和，存在碱耗高、产生固废、重金属再溶解等缺点。钒 (V) 行业也存在类似问题。本研究旨在最大限度地减少含氟废水的产生，通过在 V 提取过程的某些阶段内部再利用残液来减少 CaF ₂的消耗。在残液回用浸出过程中，残液中的Al-F络合物在硫酸的作用下分解生成HF。这增强了白云母的破坏并提高了 V 的浸出效率。响应面法 (RSM) 用于优化萃余液再浸出过程，并且当 CaF ₂用量从 3 wt.% 减少到 1.8 wt.%，H ₂ SO ₄浓度低至 14 vol%，该过程保持了超过 86% 的最佳 V 回收效率。该方法可实现100%的萃余液回用率，在钒浸出行业具有巨大的应用潜力。