Platinum Recovery via Dual Ionic Liquid Electrolysis

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Solution Overview

Problem

Current platinum recovery processes, such as pyrometallurgical and hydrometallurgical methods, are energy-intensive, environmentally hazardous, and inefficient, with electrochemical methods facing issues of reproducibility and safety due to uncontrolled reactions and harmful gas emissions.

Innovation Solution

An electrochemical process using a dual ionic liquid electrolytic solution comprising a first organic cation and inorganic anion, and a second organic or inorganic anion, which allows for controlled platinum recovery on the negative electrode without harmful gas release, optimizing industrial safety and environmental impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pyrometallurgical processes are used to recover platinum, then platinum recovery is effective, but energy consumption increases and harmful gases are released

Engineering Contradiction:
Improveplatinum recovery effectivenessVSAvoidharmful gas emissions
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the fundamental parameter of the recovery process from thermal (pyrometallurgical) to electrochemical. By applying electrical potential instead of high temperatures, the process achieves effective platinum recovery while operating at ambient or moderate temperatures, thereby eliminating the formation of harmful gases such as CO2, SO2, and HF that result from combustion at 1400-1700°C.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces the mechanical/thermal system (heating to very high temperatures in a plasma arc furnace) with an electrochemical system (electrolysis in ionic liquid). This substitution maintains the effectiveness of platinum recovery while eliminating the harmful thermal effects that cause gas emissions and energy consumption.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If aqua regia is used to dissolve platinum, then platinum and other components can be recovered, but industrial safety risks increase due to concentrated acid handling

Engineering Contradiction:
Improveplatinum dissolution effectivenessVSAvoidindustrial safety risks
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the chemical environment from highly acidic (aqua regia with concentrated HCl and HNO3) to neutral or mildly basic ionic liquid. This parameter change maintains the ability to dissolve and recover platinum while eliminating the corrosive and hazardous properties of concentrated acids, thereby reducing industrial safety risks associated with acid handling and effluent treatment.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses ionic liquid as an intermediary medium that enables platinum dissolution without the need for harmful concentrated acids. The ionic liquid acts as a safe, non-corrosive alternative that provides the necessary chemical environment for electrochemical dissolution while eliminating the safety hazards of traditional acid-based methods.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of energy

If electrochemical methods are used to recover platinum, then energy consumption is reduced, but reproducibility and safety decrease due to uncontrolled reactions

Engineering Contradiction:
Improveenergy consumptionVSAvoidprocess reproducibility and safety
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The invention changes the electrolyte parameter from traditional aqueous solutions to ionic liquid. This change provides a stable, non-volatile, and chemically inert environment that enables controlled electrochemical reactions. The ionic liquid's unique properties (low vapor pressure, high thermal stability, wide electrochemical window) ensure reproducible results and safe operation while maintaining low energy consumption.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates an inert chemical environment using ionic liquid as the electrolyte medium. This inert environment prevents uncontrolled side reactions, ensures reproducible electrochemical dissolution of platinum, and enhances safety by eliminating volatile and reactive components present in traditional aqueous electrolyte systems.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

4Device complexity

If single ionic liquid electrolytic solution is used, then process simplicity is improved, but platinum recovery selectivity and efficiency decrease

Engineering Contradiction:
Improveelectrolytic solution compositionVSAvoidplatinum recovery selectivity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The invention uses a composite electrolytic solution formed by combining two complementary ionic liquids. This composite system leverages the strengths of each component: one ionic liquid facilitates platinum dissolution while the other enhances platinum deposition selectivity. The synergistic combination achieves high recovery efficiency and selectivity while maintaining relatively simple process operation.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention segments the electrolytic solution into two functional components, each ionic liquid performing a specific function in the platinum recovery process. This segmentation allows optimization of each component's properties for its specific role (dissolution vs. deposition), thereby achieving high selectivity and efficiency without excessive overall complexity.

Inventive Principle:
Principle #1Segmentation

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 process achieves efficient and selective platinum recovery in a single step as pure metallic platinum, reducing energy and processing costs, and ensuring environmental safety by avoiding harmful gas emissions.

Implementation Method 1

The invention relates to a process for recovering platinum from a material in which this platinum is contained, this process being characterised in that it comprises an electrolysis step carried out in an electrolytic solution

Methodology Applied
Scientific EffectElectrolysis: Electrolysis

Implementation Method 2

the anodic dissolution of the metallic platinum constituting the anode, the majority anodization product thus formed being constituted by Pt +IV

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 3

the cathodic deposition of metallic platinum on the cathode

Methodology Applied
Scientific EffectElectrodeposition: Electrodeposition

Data Source

PatentEP3263744B1Process for the recovery of platinum, electrochemically, from a material which contains same
Publication Date: 2019.05.15 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP3263744B1 patent drawingFigure 1~2
  • EP3263744B1 patent drawingFigure 3~4
  • EP3263744B1 patent drawingFigure 5~6A

AI summary

The invention relates to a process for recovering platinum from a material in which it is contained, this process comprising an electrolysis step conducted in an electrolytic solution in which is immersed a system comprising a positive electrode and a negative electrode connected to a device for controlling the potential of one of the two positive and negative electrodes, the material being disposed on the positive electrode and the electrolytic solution comprising a first ionic liquid LI1. LI1 is formed by a first organic cation and a first inorganic anion selected from the group consisting of halide, dicyanamide and thiocyanate anions, and the electrolytic solution further comprises a second ionic liquid LI2 formed by a second organic cation and a second anion selected from the group consisting of TFSI-, FSI-, CF3SO3-, FAP- and BOB- anions, by means of which the platinum is recovered on the negative electrode.The invention also relates to a method for recovering platinum contained in fuel cell electrodes which implements the previous method.