Heavy Rare Earth Magnet Recycling via Fluorinated Residue Extraction
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Solution Overview
Problem
Existing methods for recycling rare earth magnets and heavy rare earth elements face challenges such as increased raw material costs, environmental impact, and inefficient separation of light and heavy rare earth elements, leading to complex separation steps and low recycling rates.
Innovation Solution
A method involving fluorination of coarse particles from molten salt electrolysis residues, followed by pulverization and mixing with R-M or R-M-B alloys, and heating to separate and extract heavy rare earth elements into an alloy form, which can be reused as a raw alloy for rare earth magnets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If additional flux materials are added to extract rare earth elements from scrap, then the extraction efficiency is improved, but the raw material costs and environmental impact increase
Solution Approach 1:
The invention uses the molten salt electrolysis residue itself as the flux material to extract heavy rare earth elements. The residue, which would normally be discarded, is reused to facilitate the extraction process, eliminating the need for additional flux materials and reducing both costs and environmental impact while maintaining extraction efficiency
Solution Approach 2:
The invention recovers valuable heavy rare earth elements from what would otherwise be waste molten salt electrolysis residue. By treating the residue as a resource rather than waste, the process extracts Dy and Tb while simultaneously finding useful application for the residue itself as a flux material
2Device complexity
If conventional recycling methods are used to separate heavy rare earth elements, then the recycling process is simplified, but the separation efficiency and purity are reduced
Solution Approach 1:
The invention changes the chemical parameters of the system by using fluorinated molten salt electrolysis residue, which creates specific chemical conditions that enable selective extraction of heavy rare earth elements. The fluorination process and specific composition ratios create optimal conditions for separating Dy and Tb from light rare earth elements while maintaining process simplicity
Solution Approach 2:
The invention selectively extracts only the heavy rare earth elements (Dy and Tb) from the mixed rare earth content in the scrap and residue, leaving light rare earth elements behind. This selective extraction achieves high separation efficiency and purity for the target elements without requiring complex multi-step separation processes
3Reliability
If molten salt electrolysis is used to produce heavy rare earth metals, then the heat resistance of rare earth magnets is improved, but the supply stability and price fluctuation risks increase
Solution Approach 1:
The invention recovers heavy rare earth elements from recycled scrap and residue, creating a closed-loop recycling system. This reduces dependence on primary raw material supplies from molten salt electrolysis, stabilizing the supply chain and reducing price volatility while maintaining the heat resistance benefits of heavy rare earth-containing magnets
Solution Approach 2:
The recycling process handles multiple input streams (scrap, residue) and produces a versatile alloy composition that can be used to manufacture new rare earth magnets with the required heat resistance. The process is adaptable to varying input compositions while maintaining consistent output quality
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 efficiently recycles heavy rare earth elements in alloy form, reducing raw material costs and environmental impact, while improving recycling rates and maintaining magnetic properties of the final product.
Implementation Method 1
a step of mixing coarse particles of the heavy rare earth element-containing molten salt electrolysis residue with a fluorinating material followed by firing, to fluorinate the coarse particles of the molten salt electrolysis residue
Implementation Method 2
a step of mixing the powder of the fluorinated molten salt electrolysis residue with R, an R-M alloy, or an R-M-B alloy, heating and melting the mixture, separating a molten alloy from slag, and selectively extracting the heavy rare earth element into the molten alloy
Implementation Method 3
a step of mixing the powder of the fluorinated molten salt electrolysis residue with R, an R-M alloy, or an R-M-B alloy, heating and melting the mixture, separating a molten alloy from slag
Data Source
AI summary
A method for collecting a heavy rare earth element from a molten salt electrolysis residue and recycling the heavy rare earth element that includes mixing coarse particles of the molten salt electrolysis residue with a fluorinating material followed by firing to fluorinate the coarse particles, pulverizing the fluorinated coarse particles to obtain a powder, and mixing the powder with R, an R-M alloy, or an R-M-B alloy, where R is a rare earth element selected from Y, La, Ce, Nd, Pr, Sm, Gd, Dy, Tb, and Ho, M is a transition metal such as Fe or Co, and B is boron, heating and melting the mixture, separating a molten alloy from slag, and selectively extracting the heavy rare earth element into the molten alloy. The method can efficiently recycle a heavy rare earth element in an alloy form, useful for recycling a rare earth magnet.