[REEs] 加速稀土金屬提煉進程 Speeding up the rare earth metal refining process

稀土金屬精煉製程速度慢、複雜且耗能，這主要是因為稀土元素的化學性質非常相似，導致分離困難。加快這項製程需要採用製程強化和新型分離技術，以減少步驟數量、試劑消耗和總時間。

The process of rare earth metal refining is notoriously slow, complex, and energy-intensive, primarily because the elements have very similar chemical properties, making their separation difficult. Speeding up the process involves adopting process intensification and novel separation technologies to reduce the number of steps, consumption of reagents, and overall time.

以下是加速稀土金屬精煉的關鍵策略和新興技術：

Here are the key strategies and emerging technologies to accelerate rare earth metal refining:

1. Advancements in Separation Techniques 分離技術的進步

傳統的工業分離方法，主要是溶劑萃取（液-液萃取），雖然效率很高，但需要數百個混合澄清器級才能達到高純度，耗時耗力。新方法旨在以更少的步驟實現分離：

Traditional industrial separation, primarily solvent extraction (liquid-liquid extraction), is highly effective but requires hundreds of mixer-settler stages to achieve high purity, which is time-consuming. New methods aim to achieve separation in far fewer steps:

    Solid-Phase Extraction (SPE 固相萃取) / Adsorption: This involves using specialized adsorbent materials (like metal-organic frameworks (MOFs), mesoporous materials, or functionalized polymers) that have high selectivity to bind rare earth elements (REEs) from the solution.

        Benefit: Rapid adsorption kinetics, significantly lower solvent consumption, and fewer stages compared to solvent extraction.

    Nanotrap Structures 奈米阱結構: Rationally designed materials, such as specific MOFs, are being developed as "nanotraps" that are highly responsive to the size variation of different rare-earth ions, potentially allowing for high-efficiency separation in a single step.

    Membrane Separation: Utilizing specialized membranes that allow selective passage of different rare-earth ions can streamline the separation process.

    Ionic Liquids and Deep Eutectic Solvents 離子液體和低共熔溶劑: These are alternative, often less toxic, and highly tunable solvents that can be designed for improved selectivity and efficiency in the extraction process, potentially reducing the number of separation cycles needed.

2. Process Intensification and Optimization 流程強化與最佳化

Intensification focuses on making existing steps faster, smaller, and more efficient through engineering and control:

    Continuous Countercurrent Processes 連續逆流工藝: Optimizing the flow in solvent extraction using continuous multi-stage counterflow separators (like advanced mixer-settler cells) can maximize efficiency and throughput.

    Microwave-Assisted Extraction (MAE 微波輔助萃取) and Subcritical Water Extraction (SWE 亞臨界水萃取): Applying microwave energy or using water in its subcritical state can accelerate the initial leaching of REEs from the ore concentrate or secondary sources (like electronic waste), reducing reaction times.

    AI-Enabled Process Control 人工智慧製程控制: Using Artificial Intelligence (AI) and Machine Learning (ML) to monitor and control the complex chemical conditions (like pH, temperature, and reagent flow) in real-time can optimize the separation process, ensuring maximum yield and speed while minimizing errors and resource waste.

3. Streamlined Conversion to Metal 簡化的金屬轉換

The final step of converting rare earth oxides (REOs) or salts to high-purity metal can also be a bottleneck. Novel methods can eliminate intermediate steps:

    REMAFS (Rare Earth Metals from Alternative Fluoride Salt 來自替代氟化鹽的稀土金屬): This new process bypasses the traditional step of converting the separated rare-earth oxides back into a fluoride salt before reduction to metal. By starting with a specific sodium rare-earth fluoride salt, the number of overall steps is reduced, cutting out time and cost.

    Electrochemical/Electrolytic Refining 電化學/電解精煉: While conventional for some REEs, improving the efficiency of the molten salt electrolysis process—which converts the rare-earth compounds into metal—can lead to faster production rates.

4. Alternative Feedstock Utilization (Recycling) 回收

Focusing on secondary sources (recycling) can sometimes be faster than processing raw ore, which requires extensive crushing, milling, and beneficiation:

    Direct Recycling 直接回收: Developing direct methods to recover REEs from end-of-life products (like magnets in hard drives or electric vehicle batteries) can skip much of the initial "rock to concentrate" stage, leading to a quicker overall cycle.

    Flash Heating Isolation 閃蒸加熱隔離: A recently developed technique involves "flash heating" materials like fly ash (containing REEs) with a quick, high-current pulse. This can shatter glass microstructures that encapsulate the metals and convert less-soluble compounds into more extractable oxides in seconds, drastically speeding up the pre-leaching preparation.

Picture Source: Copilot

Picture Source: Gemini

CONTENT SOURCE: Gemini.