CO2-Assisted Solvent Separation of Heavy Rare Earth Elements
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for extracting rare earth elements (REEs) face challenges in complex component separation from solutions containing multiple metals, particularly in electrochemical environments, leading to issues with solvent degradation and stability.
Innovation Solution
A method involving the use of an aqueous solution with rare earth metal ions and base metal ions, where carbon dioxide is captured using a solvent, allowing for the formation of a rare earth metal carbonate through the introduction of a source of (bi)carbonate or carbamate anion, enabling effective separation of the rare earth metal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional solvent extraction methods are used for rare earth element recovery, then extraction efficiency is improved, but complex component separation from multi-metal solutions becomes difficult
Solution Approach 1:
The patent changes the chemical parameters of the solution by adjusting pH levels and introducing specific reagents that selectively precipitate rare earth elements as carbonates while leaving base metals in solution. This parameter-based separation enables efficient extraction without complex multi-step procedures.
Solution Approach 2:
The invention extracts rare earth elements from multi-metal solutions by selectively removing them through carbonate precipitation. The method takes out the target rare earth metals from the complex mixture, separating them from base metals through controlled chemical reactions that exploit differences in solubility and precipitation behavior.
2Productivity
If conventional extraction methods are applied to electrochemical environments, then rare earth metal recovery is achieved, but solvent degradation and stability issues occur
Solution Approach 1:
The patent employs disposable or easily replaceable reagents and solvents that can be regenerated or discarded without causing environmental harm. The method uses readily available chemicals for carbonate precipitation that can be separated and reused, eliminating the need for stable, expensive, and environmentally persistent solvents in electrochemical environments.
Solution Approach 2:
The invention recovers and reuses valuable rare earth metal products while discarding or regenerating the solvent system. The method facilitates the recovery of rare earth metals as pure carbonate precipitates, which can then be processed into final products, while the remaining solution can be treated to recover base metals or simply discarded if inexpensive.
3Adaptability or versatility
If multi-component separation is performed in electrochemical solutions, then comprehensive metal recovery is achieved, but process complexity and contamination increase
Solution Approach 1:
The patent segments the separation process into distinct stages: first precipitating rare earth elements as carbonates, then separately recovering base metals from the remaining solution. This segmentation allows each component to be purified independently, achieving high separation purity while maintaining the ability to handle multi-element solutions.
Solution Approach 2:
The invention uses carbonate ions as an intermediary substance that selectively interacts with rare earth metal ions to form insoluble precipitates. This intermediary mechanism enables clean separation between rare earth metals and base metals, preventing direct contamination between the two metal recovery processes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method achieves efficient recovery and separation of rare earth metals with high purity, overcoming the challenges of multicomponent separation in electrochemical environments, while also promoting a circular economy and mitigating greenhouse gas emissions.
Implementation Method 1
adding a solvent to capture carbon dioxide (CO2) to the aqueous solution
Implementation Method 2
introducing a source of (bi)carbonate or carbamate anion into the solution, thereby forming a rare earth metal carbonate; precipitating the rare earth metal carbonate from the aqueous solution
Data Source
AI summary
Provided are methods for recovering a rare earth metal from an aqueous solution containing at least two metals. The methods entail: providing an aqueous solution containing rare earth metal ions from a rare earth metal and base metal ions from a base metal that is a transition metal; adding to the aqueous solution a solvent to capture carbon dioxide; and recovering the rare earth metal by: introducing a source of (bi)carbonate or carbamate anion into the solution, thereby forming a rare earth metal carbonate; forming a soluble base metal complex which enables separation of the rare earth element; and precipitating the rare earth metal carbonate from the aqueous solution, thereby forming a rare earth metal-depleted aqueous solution.