Lanthanide Extraction Using Organic Aprotic Solvents and Hydrotropes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for recycling rare earth elements from waste electrical and electronic equipment, such as permanent magnets, are inefficient and require high amounts of toxic and aggressive reagents, leading to environmental and health risks, and often result in complex, multi-step processes with low extraction yields.
Innovation Solution
A method using a leaching composition comprising an aqueous phase, an organic aprotic solvent, and a charged hydrotrope to selectively extract lanthanide elements from solid materials, reducing the need for toxic reagents and allowing for smoother leaching conditions, thereby improving extraction selectivity and efficacy while enabling recycling of main reactants and solvents in a closed cycle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional hydrometallurgical methods are used to extract lanthanide elements from permanent magnets, then extraction can be achieved, but high amounts of toxic and aggressive reagents are required, leading to environmental and health risks
Solution Approach 1:
The patent changes the chemical parameters of the extraction system by using a specific composition of organic aprotic solvent (cyrene, gamma-valerolactone, or dihydrolevoglucosenone) combined with charged hydrotropes (sodium salicylate, sodium xylene sulfonate, sodium cumene sulfonate, or sodium toluene sulfonate) instead of conventional toxic reagents. This parameter change maintains extraction efficiency while eliminating harmful effects.
Solution Approach 2:
The patent employs a composite extraction system combining multiple components: organic aprotic solvent molecules, charged hydrotrope salts, and water. This composite approach creates a synergistic effect that enables effective lanthanide extraction without requiring single-component toxic reagents, thus resolving the contradiction between extraction efficiency and reagent toxicity.
2Productivity
If conventional multi-step processes are used for recycling rare earth elements, then some extraction can be achieved, but the processes are complex and require high amounts of reagents
Solution Approach 1:
The patent merges multiple extraction functions into a single step by using a specialized composition that simultaneously extracts lanthanide elements while maintaining selectivity. The combination of organic aprotic solvent and charged hydrotrope in one aqueous-organic two-phase system eliminates the need for multiple sequential treatment steps, thereby reducing process complexity while maintaining high extraction yield.
Solution Approach 2:
The extraction composition serves multiple functions simultaneously: it extracts lanthanide elements, separates them from iron and other waste elements, and can be recycled in a closed cycle. This multi-functionality reduces the need for separate processing steps, simplifying the overall process while maintaining high productivity.
3Manufacturing precision
If selective extraction of lanthanide elements is performed, then separation from waste elements is achieved, but extraction yields remain low in conventional methods
Solution Approach 1:
The patent optimizes the chemical parameters of the extraction system by adjusting the type and concentration of organic aprotic solvent and charged hydrotrope. This parameter optimization enables the system to achieve both high separation selectivity for lanthanide elements from iron and other waste elements, and high extraction yield, thereby resolving the contradiction between precision and productivity.
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
The method achieves selective extraction of lanthanide elements with high efficiency, reducing environmental and health risks, and simplifies the process by enabling simultaneous separation of lanthanides from waste elements like iron, with high recovery rates and reduced waste generation.
Implementation Method 1
mixing the leaching composition with the solid material so as to form a leachate solution comprising the first lanthanide element
Implementation Method 2
preparing a leaching composition comprising an aqueous phase, at least one organic aprotic solvent, and at least one charged hydrotrope
Data Source
AI summary
A method for extracting at least one lanthanide element, preferably selected from lanthanum (La), praseodymium (Pr), neodymium (Nd), europium (Eu), dysprosium (Dy), and ytterbium (Yb), from a solid material including the lanthanide element, one or more waste elements such as iron (Fe), and/or one or more other lanthanide elements. The method implements a composition including water, at least one organic aprotic solvent, and at least one charged hydrotrope. Also, the use of the composition for recycling lanthanide elements, and more particularly WEEE, and for the decontamination of effluents.