Rare Earth Separation via Valence State Conversion
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Solution Overview
Problem
Current methods for separating rare earth elements from rare earth magnets are costly due to the similarity in chemical properties of these elements, leading to high production costs and resource inefficiencies, particularly in recycling and recovering rare earth elements from waste materials.
Innovation Solution
A method involving a series of processing steps including oxidation heat treatment, powder size optimization, chlorination, and oxychlorination to separate rare earth oxides and chlorides, allowing for selective dissolution and separation of specific rare earth elements, utilizing a chlorinating agent like ammonium chloride to achieve a high separation ratio at a lower cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional separation methods are used for rare earth elements, then separation can be achieved, but the production cost is high due to the similarity in chemical properties of rare earth elements
Solution Approach 1:
The patent changes the chemical parameters of rare earth elements by controlling oxidation states. Trivalent rare earth elements are converted to divalent state through reduction, creating a valence state difference that enables separation. This parameter change (from trivalent to divalent) exploits the chemical property difference between rare earth elements to achieve separation without costly conventional methods
Solution Approach 2:
The patent creates local quality differences by forming divalent rare earth halides specifically from trivalent rare earth elements, while leaving other rare earth elements in their original state. This localized chemical transformation allows selective separation of specific rare earth elements based on their divalent halide formation properties
2Loss of substance
If recycling techniques are developed to extract rare earth elements from waste materials, then resource efficiency improves, but the separation cost remains high
Solution Approach 1:
The patent applies parameter changes by converting rare earth element valence states during the recycling process. By reducing trivalent rare earth elements to divalent state and forming divalent halides, the method enables cost-effective separation from waste materials, improving resource efficiency while reducing separation costs compared to conventional recycling techniques
3Manufacturing precision
If multiple processing steps are used to separate rare earth elements, then separation purity is improved, but the process complexity increases
Solution Approach 1:
The patent reduces process complexity by using a single key parameter change (valence state conversion from trivalent to divalent) that simultaneously achieves both separation and purification. This one-step chemical transformation creates sufficient property differences to separate rare earth elements without requiring multiple complex processing steps
Solution Approach 2:
The patent segments rare earth elements into two groups based on their ability to form divalent halides: those that can be reduced to divalent state and those that cannot. This segmentation strategy simplifies the separation process by creating distinct chemical behavior groups that can be separated through selective halogenation
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 effectively separates and recovers rare earth elements with a high separation ratio, reducing production costs and improving resource efficiency by optimizing powder size and using controlled chlorination and oxychlorination processes.
Implementation Method 1
a chlorinating agent mixing step of mixing the rare earth oxide powder obtained at the powder size optimization step with a chlorinating agent to prepare a 'rare earth oxide powder'/'chlorinating agent' mixture
Implementation Method 2
a chlorination/oxychlorination heat treatment step of forming a 'first group rare earth chlorides'/'second group rare earth oxychlorides' mixture including first group rare earth chlorides and second group rare earth oxychlorides from the 'rare earth oxide powder'/'chlorinating agent' mixture
Implementation Method 3
a chlorination/oxychlorination heat treatment step of forming a 'first group rare earth chlorides'/'second group rare earth oxychlorides' mixture
Implementation Method 4
a chlorination/oxychlorination heat treatment step of forming a 'first group rare earth chlorides'/'second group rare earth oxychlorides' mixture from the 'rare earth oxide powder'/'chlorinating agent' mixture
Implementation Method 5
introducing the 'first group rare earth chlorides'/'second group rare earth oxychlorides' mixture in a solvent in order to selectively dissolve the first group rare earth chlorides in the solvent and leave the second group rare earth oxychlorides undissolved in solid phase form
Implementation Method 6
solid-liquid separating the solvent in which the first group rare earth chlorides are dissolved and the second group rare earth oxychlorides in the solid phase form
Implementation Method 7
a magnet component oxidation heat treatment step of forming a powder of oxides of the magnet components, the oxides being formed by heating or combustion at a temperature from 300 to 1000° C. in an oxidizing atmosphere
Data Source
AI summary
An objective of the invention is to provide a method and system for separating a particular rare earth element from a rare earth magnet at a high separation ratio and by a simple process. There is provided a rare earth separation method for separating a first and a second groups of rare earth elements contained in a magnet, the method including: a starting powder preparation step from the magnet; a magnet component oxidation heat treatment step; a rare earth oxide separation step from the magnet components oxide powder; a powder size optimization step; a chlorinating agent mixing step; a chlorination/oxychlorination heat treatment step of forming a “first group rare earth chlorides”/“second group rare earth oxychlorides” mixture; a selective dissolution step of selectively dissolving the first group rare earth chlorides in the solvent and leaving the second group rare earth oxychlorides undissolved in solid phase form; and a solid-liquid separation step.