Composite Extractant Resin for Rare Earth Slurry Phase Separation

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Solution Overview

Problem

Current solvent extraction processes face challenges such as solvent loss, incomplete phase separation, emulsion formation, crud formation, and poor economics when dealing with acid-leaching slurries containing high solids content and low concentrations of rare earth metals, particularly scandium, due to issues like emulsion stability and high interference from ferric and titanium ions.

Innovation Solution

A composite extractant-enhanced polymer resin, comprising organophosphorus acids and phosphoric acid groups, is used to directly extract rare earth metals from acid-leaching slurries, allowing for efficient separation and recovery of metals like scandium by mixing with the slurry, followed by stripping and regeneration of the resin.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If traditional solvent extraction is used on acid-leaching slurry, then rare earth metals can be extracted, but emulsion formation occurs and phase separation becomes incomplete

Engineering Contradiction:
Improverare earth metal extractionVSAvoidphase separation completeness
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent uses a co-solvent (such as xylene, toluene, or kerosene) as an intermediary substance added to the organic extractant phase. This co-solvent acts as a mediator that reduces the interfacial tension between the aqueous and organic phases, preventing emulsion formation and facilitating complete phase separation while maintaining effective rare earth metal extraction

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the chemical composition parameters of the organic phase by adding specific co-solvents in controlled amounts (typically 5-50% by volume). This parameter change alters the physical properties of the organic phase, including its polarity and interfacial tension, thereby preventing emulsion stability and enabling complete phase separation

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If traditional solvent extraction is used on acid-leaching slurry, then rare earth metals can be extracted, but solvent loss increases due to emulsion stability

Engineering Contradiction:
Improverare earth metal extractionVSAvoidsolvent loss
Core Design Contradiction:
Quantity of substanceVSLoss of substance

Solution Approach 1:

The co-solvent serves as an intermediary that breaks the stable emulsion structure, allowing the organic solvent to separate completely from the aqueous phase. This prevents solvent entrapment in stable emulsions and reduces solvent loss, while the extractant remains effective at extracting rare earth metals

Inventive Principle:
Principle #24Intermediary (Mediator)

3Quantity of substance

If traditional solvent extraction is used on acid-leaching slurry, then rare earth metals can be extracted, but crud formation occurs

Engineering Contradiction:
Improverare earth metal extractionVSAvoidcrud formation
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The co-solvent acts as an intermediary that modifies the interaction between the organic phase and solid particles in the slurry. It reduces the adhesion of fine solid particles (crud) to the organic phase interface, preventing crud formation while maintaining the extractant's ability to transfer rare earth metals to the organic phase

Inventive Principle:
Principle #24Intermediary (Mediator)

4Productivity

If intensive mixing is applied to ensure complete metal transfer, then extraction efficiency improves, but emulsion formation increases

Engineering Contradiction:
Improvemetal transfer completenessVSAvoidphase separation feasibility
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The co-solvent is added to the organic phase before mixing with the aqueous slurry. It performs a preliminary anti-action by pre-conditioning the organic phase to resist emulsion formation during intensive mixing, allowing complete metal transfer without creating stable emulsions that would hinder subsequent phase separation

Inventive Principle:
Principle #9Preliminary anti-action

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 composite resin achieves high recovery rates of rare earth metals, including scandium, with minimal solvent loss and improved phase separation, even in the presence of high ferric ions, thus overcoming the limitations of traditional methods.

Implementation Method 1

The composite extractant-enhanced polymer resin is used to directly extract rare earth metals from acid-leaching slurries

Methodology Applied
Scientific EffectSolvent extraction: Liquid-Liquid Extraction

Implementation Method 2

The extractant comprises at least one functional group selected from organophosphorus acids

Methodology Applied
Scientific EffectComplexation: Chemical Bonding

Implementation Method 3

the mixture slurry or solution is separated into a rare-earth-metal-loaded composite and a raffinate slurry or solution

Methodology Applied
Scientific EffectPhase separation: Liquid-Liquid Extraction

Data Source

PatentEP4104923B1Use of composite extractant for extracting rare earth metals from an acid-leaching slurry or an acid-leaching solution
Publication Date: 2026.03.25 II VI INC
  • EP4104923B1 patent drawingFigure 1
  • EP4104923B1 patent drawingFigure 2
  • EP4104923B1 patent drawingFigure 3

AI summary

The invention relates to a composite extractant for extracting rare earth metals from an acid-leaching slurry or an acid-leaching solution, the composite comprising: an extractant and a polymer resin, the polymer resin having at least one resin functional group, wherein the at least one resin functional group includes an anion functional group, or a cation functional group, or an anion functional group and a cation functional group.