Ionic Liquid Extraction for Selective Iron Removal
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Solution Overview
Problem
Current methods for removing iron from coal gangue leachates, such as precipitation, are inefficient due to low selectivity and generate environmentally hazardous fine precipitates, while solvent extraction using traditional organic solvents poses environmental and safety hazards.
Innovation Solution
The use of phosphonium or ammonium salt ionic liquids, like Cyphos IL 101 and Aliquat 336, as both extractants and solvents for selective iron removal from coal gangue leachates through liquid-liquid extraction, allowing for the separation of Fe(III) ions from other metals like aluminum without the need for additional organic solvents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If precipitation method is used to remove iron from leach solutions, then iron removal is achieved, but selectivity is low due to co-precipitation and fine precipitates are generated which are difficult to remove
Solution Approach 1:
The patent applies extraction principle by using ionic liquids to selectively extract Fe(III) ions from leach solutions. The ionic liquid phase selectively takes out iron from the aqueous phase through liquid-liquid extraction, avoiding co-precipitation issues and enabling high-selectivity separation of iron from other metal ions in the solution.
Solution Approach 2:
The patent changes the chemical parameters of the extraction system by using ionic liquids with specific functional groups and properties. By adjusting ionic liquid composition, concentration, and extraction conditions, the system achieves high selectivity for iron removal while preventing co-precipitation of other metals, thus resolving the selectivity contradiction.
2Manufacturing precision
If traditional organic solvents are used for solvent extraction, then metal ion separation is achieved, but environmental and workplace hazards arise due to flammability, volatility or toxicity
Solution Approach 1:
The patent fundamentally changes the physical and chemical parameters of the extraction medium by replacing traditional volatile organic solvents with ionic liquids. Ionic liquids have negligible vapor pressure, non-flammability, and tunable properties, thereby eliminating environmental and safety hazards while maintaining high metal ion separation efficiency through adjustable extraction parameters.
Solution Approach 2:
The patent uses composite ionic liquid systems combining different cations and anions to create tailored extraction media. These composite ionic liquids integrate the benefits of low volatility, non-flammability, and high selectivity for metal ion separation, resolving both the separation efficiency and environmental safety requirements simultaneously.
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 process achieves high selectivity and efficiency in removing Fe(III) ions, resulting in high-purity aluminum products and reducing environmental concerns by using 'green' ionic liquids that are safer and more cost-effective.
Implementation Method 1
contacting the feedstock with an organic phase comprising a phosphonium salt or ammonium salt ionic liquid under liquid-liquid extraction conditions for a time sufficient to allow transfer of at least some of the Fe(III) ions from the feedstock to the organic phase
Data Source
AI summary
This disclosure relates to a process for selectively extracting Fe(III) ions from an aqueous feedstock containing Fe(III) ions and non-ferric ions. The process comprises contacting the feedstock with an organic phase comprising a phosphonium salt or ammonium salt ionic liquid under liquid-liquid extraction conditions for a time sufficient to allow transfer of at least some of the Fe(III) ions from the feedstock to the organic phase to provide an Fe(III) ion laden organic phase and an Fe(III) depleted feedstock, and separating the Fe(III) ion laden organic phase from the Fe(III) depleted feedstock.