Solvent Extraction Partial Reflux for Rare Earth Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current solvent extraction methods for rare earth elements (REEs) require a large number of stages due to low separation factors, particularly for Nd/Pr and Pr/Ce separations, leading to inefficient processing and the need for additional chemical steps to achieve high purity REEs.
Innovation Solution
Implementing a process that involves multiple contacts of REEs with a solvent containing a diluent and/or modifier, along with partial reflux of specific REEs to enhance separation factors, reducing the number of stages and eliminating the need for pre-chemical processing for cerium separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional solvent extraction methods are used for REE separation, then the process can achieve separation of rare earth elements, but a large number of stages are required due to low separation factors
Solution Approach 1:
The invention changes the chemical parameters of the system by introducing selective complexing agents that form stable complexes with specific REE ions. This alters the distribution coefficients and separation factors, enabling high-purity separation in fewer stages. The complexing agents modify the chemical environment to enhance the differential extraction behavior between adjacent REE elements.
Solution Approach 2:
The invention uses composite extractant systems combining multiple extractants with different selectivities. This composite approach leverages the synergistic effects of different extractants to achieve enhanced separation factors for challenging REE pairs, reducing the number of stages required while maintaining high purity separation.
2Manufacturing precision
If conventional solvent extraction methods are used for REE separation, then the process can separate rare earth elements, but additional chemical steps are required to achieve high purity REEs
Solution Approach 1:
The invention performs preliminary group separation to concentrate specific REE elements into separate streams before final purification. This preliminary concentration step simplifies the subsequent separation process by reducing the complexity of the feed composition, allowing high-purity separation to be achieved with fewer additional chemical steps.
Solution Approach 2:
The invention selectively extracts specific REE elements from the mixture using tailored extractant systems. By taking out target REE elements in concentrated forms through selective complexation and extraction, the process eliminates the need for multiple sequential separation steps, simplifying the overall process while achieving high purity.
3Manufacturing precision
If conventional solvent extraction methods are used for REE separation, then the process can achieve REE separation, but processing efficiency is reduced due to low separation factors
Solution Approach 1:
The invention modifies the extraction parameters by controlling pH, temperature, and extractant concentration to optimize separation factors. These parameter changes enhance the differential distribution of REE elements between organic and aqueous phases, improving both separation quality and processing efficiency simultaneously.
Solution Approach 2:
The invention employs dynamic extraction conditions where pH and other parameters are adjusted during the extraction process to maintain optimal separation factors. This dynamic approach allows the system to adapt to different REE compositions and maintain high processing efficiency throughout the separation process.
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 approach significantly reduces the number of separation stages required, achieving high purity REEs with fewer cycles and eliminating the need for pre-chemical processing, thereby improving efficiency and cost-effectiveness in REE extraction.
Implementation Method 1
solvent extraction is most widely used for production of tonnage quantities of highly pure individual REEs. It depends on the preferential distribution of individual REEs (either in the cationic form or as complex anions or as neutral species) between two immiscible liquid phases that are in contact with each other.
Data Source
AI summary
A process of solvent extraction for separation of rare earth elements (REEs) based on separation factor is provided. The method includes repeatedly contacting the REEs containing aqueous solution with a suitable solvent containing a diluent and/or a modifier and an REE as a partial reflux.