Abstract

A stable and continuous leaching process for niobium and tantalum extraction from ferrocolumbium tantalum (FT) was developed. The effects of initial concentration of HF and H₂SO₄, grinding fineness, leaching time, and temperature on the leaching rate of Ta, Nb, Fe, and Si were studied. Experimental results show that the leaching rates of Ta, Nb, Fe, and Si were enhanced by the increase of acid concentrate, fineness, leaching time, and leaching temperature. The optimum process conditions are HF initial concentration of 5 mol/L, H₂SO₄ initial concentration of 2.5 mol/L, − 74 µm percentage of 65%, leaching time of 20 min, and leaching temperature of 25 °C. Continuous leaching of FT was carried out by feeding ore and acid every 20 min. By leaching with HF − H₂SO₄ for 4 h, then adding appropriate amount of HNO₃ into the solution and keeping for another 1 h, a high Nb extraction rate of 99.8% was achieved. The established method provides a promising technique for the high-efficiency separation of niobium and tantalum from FT.

Highlights

• The priority of metal extraction in HF−H₂SO₄ system is Si > Fe > Ta > Nb.

• Ferrocolumbium tantalum can be stable leached by introducing raw material and acid every 20 min.

• A high Nb extraction rate of 99.8% was achieved by the continuous leaching process.

Graphical abstract

中文翻译：

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HF - H2SO4 - HNO3 协同系统连续浸出法从铌铁中高效回收铌和钽

摘要

开发了一种从铌铁钽（FT）中提取铌和钽的稳定连续浸出工艺。_{研究了HF和H 2} SO ₄初始浓度、研磨细度、浸出时间和温度对Ta、Nb、Fe、Si浸出率的影响。实验结果表明，随着酸精矿、细度、浸出时间和浸出温度的增加，Ta、Nb、Fe和Si的浸出率提高。最佳工艺条件为HF初始浓度为5 mol/L，H ₂ SO ₄初始浓度为 2.5 mol/L，- 74 µm 百分比为 65%，浸出时间为 20 min，浸出温度为 25 °C。FT 的连续浸出是通过每 20 分钟加入矿石和酸来进行的。用HF - H ₂ SO ₄浸出4 h，然后在溶液中加入适量HNO ₃ ，再保持1 h，Nb提取率高达99.8%。所建立的方法为从 FT 中高效分离铌和钽提供了一种有前景的技术。

强调

• HF-H ₂ SO ₄体系中金属萃取的优先级为Si > Fe > Ta > Nb。

• 每20分钟引入原料和酸可稳定浸出钽铁。

• 通过连续浸出工艺实现了 99.8% 的高 Nb 提取率。

图形概要