Metal Extraction Using Deep Eutectic Solvents and Oxidizers
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Solution Overview
Problem
Current metal extraction processes from solid materials, particularly electronic waste, face challenges such as high costs, low metal selectivity, and sensitivity to water when using Deep Eutectic Solvents (DESs) combined with iodine.
Innovation Solution
A composition comprising a Deep Eutectic Solvent (DES) and a specific oxidizer, along with a two-step process where the solid material is first contacted with a DES and a first oxidizer, followed by a second contact with a DES and a different second oxidizer, to enhance metal selectivity and recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If iodine is used as an oxidizer in DES, then metal dissolution capability is improved, but metal selectivity deteriorates
Solution Approach 1:
The patent divides the metal extraction process into multiple sequential steps, each using a different oxidizer with specific selectivity characteristics. This segmentation allows different metals to be extracted at different stages, achieving both high dissolution capability and metal selectivity that cannot be obtained with a single oxidizer system.
Solution Approach 2:
The patent changes the chemical parameters by using different oxidizers (iodine, ferric chloride, copper chloride) with varying oxidation potentials in different process steps. This parameter variation enables selective oxidation of different metals at different stages, resolving the contradiction between overall dissolution capability and metal-specific selectivity.
2Productivity
If iodine is used as an oxidizer in DES, then metal dissolution capability is improved, but cost increases
Solution Approach 1:
The patent replaces expensive iodine with cheaper alternative oxidizers like ferric chloride and copper chloride in certain process steps. These cheaper oxidizers perform the necessary metal dissolution function without requiring the high cost of iodine, thereby reducing overall reagent costs while maintaining productivity.
Solution Approach 2:
The patent varies the oxidizer selection based on which metals need to be extracted at each stage, using cost-effective oxidizers for specific metal extraction tasks rather than universally using expensive iodine for all metals, thus optimizing the cost-performance ratio.
3Productivity
If iodine is used as an oxidizer in DES, then metal dissolution capability is improved, but sensitivity to water increases
Solution Approach 1:
The patent substitutes iodine with water-tolerant oxidizers like ferric chloride and copper chloride that are less sensitive to water presence. These alternative oxidizers maintain effective metal dissolution capability while being more robust to water contamination, thereby improving process reliability.
Solution Approach 2:
The patent changes the chemical composition parameters by selecting oxidizers with different water sensitivity characteristics, using water-tolerant oxidizers in applications where water presence is unavoidable, thus maintaining productivity while reducing sensitivity to water.
4Productivity
If strong mineral acids or cyanide are used in hydrometallurgical processes, then metal extraction efficiency is improved, but environmental harm increases
Solution Approach 1:
The patent fundamentally changes the chemical parameters by using Deep Eutectic Solvents with mild oxidizers instead of strong mineral acids or cyanide. This parameter change maintains effective metal extraction while eliminating the severe environmental harm associated with traditional reagents, achieving both productivity and environmental sustainability.
Solution Approach 2:
The patent converts the traditionally harmful strong acids and cyanides into benign DES systems. By using environmentally friendly alternative chemistry that achieves similar or better extraction efficiency, the process transforms a harmful methodology into a sustainable one, eliminating pollution while maintaining productivity.
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 proposed solution achieves efficient and selective metal extraction, particularly for high-value metals like gold, while minimizing environmental impact and reducing the need for costly reagents.
Implementation Method 1
Deep Eutectic Solvents (DESs) are formed by the complexation of certain components to provide an homogeneous mixture that melts at a single temperature that is lower than the melting point of any of the constituent components
Implementation Method 2
Deep Eutectic Solvents (DESs) are formed by the complexation of certain components to provide an homogeneous mixture that melts at a single temperature
Implementation Method 3
Iodine is highly soluble in DESs and, once solubilized, it is capable of oxidising a wide range of metals
Implementation Method 4
Iodine is poorly soluble in water, making it unsuitable for most aqueous chemistries. However, it is highly soluble in DESs
Data Source
AI summary
The present invention relates to compositions and processes for the extraction of metals from solid material using non-aqueous solvents and oxidisers. The processes and compositions of the present invention are useful for selectively extracting metals from solid material, particularly electronic waste material.