Flash Joule Heating for E-Waste Metal Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for synthesizing nanomaterials like nanosized transition metal carbides and corundum nanoparticles are inefficient, leading to high costs, low productivity, and limited control over phase and crystal structure, while traditional e-waste recycling is energy-intensive and environmentally harmful, lacking in selectivity and generating hazardous byproducts.
Innovation Solution
The development of ultrafast flash Joule heating synthesis methods that apply high-voltage pulses to mixtures of e-waste with conductive additives, achieving rapid and efficient synthesis of nanomaterials and metal recovery by reaching ultrahigh temperatures in milliseconds, thereby overcoming the limitations of traditional methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional high-temperature synthesis methods are used to produce nanomaterials, then complete reaction conversion is achieved, but particle agglomeration and sintering occur resulting in large particle sizes and low surface area
Solution Approach 1:
The patent applies pulsed electric current (periodic action) to achieve flash Joule heating, where brief high-intensity heating pulses raise temperature to 2000-3000K for milliseconds, followed by rapid cooling. This periodic heating-cooling cycle enables complete reaction conversion during the heating pulse while preventing agglomeration during the cooling phase, producing nanosized particles with high surface area
Solution Approach 2:
The patent dramatically changes the temperature parameter from conventional moderate temperatures to ultrahigh temperatures (2000-3000K) achieved through flash Joule heating, and controls the duration parameter at millisecond timescales. These parameter changes enable rapid reaction completion before agglomeration can occur, simultaneously achieving high conversion efficiency and fine particle size control
2Productivity
If extended high-temperature conditions are applied to compensate for slow solid-solid reaction kinetics, then reaction completion is achieved, but sintering and agglomeration inevitably occur
Solution Approach 1:
The pulsed electric current creates periodic heating cycles where ultrahigh temperature (2000-3000K) is achieved for brief milliseconds to ensure complete reaction conversion, followed by rapid cooling that prevents sintering. This periodic action decouples reaction completion from particle growth, achieving both goals simultaneously
Solution Approach 2:
The flash Joule heating process rushes through the high-temperature reaction zone in milliseconds, completing the solid-solid reaction before agglomeration and sintering can occur. The process skips the prolonged high-temperature exposure that would otherwise cause particle growth, achieving complete conversion while maintaining nanosized particles
3Use of energy by moving object
If conventional electrical thermal processes are used for high-temperature synthesis, then energy efficiency is improved, but the ability to synthesize fine nanocrystals is limited
Solution Approach 1:
The patent uses pulsed electric current with millisecond duration to create flash Joule heating, where energy is delivered in brief intense pulses reaching 2000-3000K, followed by rapid cooling. This periodic energy delivery achieves both energy efficiency (energy is applied only when needed) and nanocrystal synthesis capability (ultrahigh temperature for brief periods prevents grain growth)
4Productivity
If traditional e-waste recycling methods are used, then metal recovery is achieved, but high energy consumption and environmental harm occur
Solution Approach 1:
The patent applies pulsed electric current to e-waste materials for flash Joule heating, delivering energy in brief millisecond pulses that reach ultrahigh temperatures for metal vaporization and condensation. This periodic energy delivery achieves complete metal recovery while consuming significantly less energy than continuous heating in traditional furnaces, and eliminates hazardous byproducts through the clean electrical heating 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 enables the production of high-surface-area nanomaterials with controlled phases and crystal structures, significantly reducing energy consumption and environmental impact, while achieving high recovery yields of precious metals from e-waste with minimal hazardous byproducts.
Implementation Method 1
applying a voltage across the mixture to recover metal from the material. The voltage is applied in one or more voltage pulses... The sample temperature can ramp to ∼3400 K in milliseconds by the ultrafast electrical thermal process
Implementation Method 2
Such a high temperature enables the evaporative separation of precious metals from the supporting matrices, with the recovery yields greater than 80% for Rh, Pd, Ag, Ir, Ru, and Pt
Data Source
AI summary
Ultrafast flash Joule heating synthesis methods and systems, and more particularly, ultrafast synthesis methods to recover precious metals recovery and other metals from electronic waste (e-waste).