In the field of metal refining and resource recovery, copper chloride water electrolysis technology has become
the core process for extracting high-purity metals and treating copper-containing wastes due to its high
efficiency and controllable characteristics. This article will systematically explain the process logic, key
control points and industrial application scenarios of this technology, and provide practitioners with
implementable technical solutions.
Technical principle and reaction mechanism
Copper chloride water electrolysis is driven by electric field to realize the directional migration and
reduction of copper elements, and its core reactions include:
Anodic oxidation: 2Cl- → Cl₂↑ + 2e-
Side reaction: Cu → Cu²⁺ + 2e- (anodic dissolution)
Cathodic reduction: Cu²⁺ + 2e- → Cu (purity 99.95%+)
Competitive reaction: 2H⁺ + 2e- → H₂↑ (inhibited at PH>3)
The reaction system exhibits a threefold characterization:
Dynamic equilibrium: chlorine ion concentration is maintained at 80-120 g/L to prevent passivation
Selective deposition: metals with standard reduction potentials lower than copper (e.g. Fe²⁺) are retained in solution
Self-regulation mechanism: anode dissolution to replenish copper ions to achieve continuous production
Six control modules for industrialized production
1. Electrolyte system construction
Process window control:
Temperature: 50-70℃ (graphite heat exchanger temperature control)
PH value: 1.5-2.5 (automatic acid-base titration system)
Circulation flow: 3-5 times the tank volume / hour
2. Optimization model of electric energy parameters
Current density: 200-400A/m² (Dk value)
Tank voltage: 2.8-3.5V (including chlorine release overpotential)
Co-pole spacing: 80-100mm (titanium-ruthenium coated electrodes)
Current efficiency: ≥92% (polarization curve monitoring)
3. Electrode system design
Anode selection: DSA coated titanium electrode (chlorine precipitation efficiency>85%)
Cathode configuration: 316L stainless steel mother plate (surface roughness Ra≤0.8μm)
Auxiliary device: titanium circulating distributor (flow rate 0.3-0.5m/s)
Typical industrial application scenarios
1. Copper-containing waste regeneration
Etching waste liquid treatment: copper recovery rate > 99
Electroplating sludge extraction: power consumption ≤1800kWh per ton of material
Product specifications: 1 # electrolytic copper (GB/T 467-2010)
2. Printed circuit board manufacturing
Through-hole filling plating: uniformity of plating layer when the depth-to-diameter ratio is 10:1＞90%.
Plating characteristics: elongation ≥15% (ASTM E8 standard)
3. Precious metal synergistic extraction
Anode sludge treatment: start recovery process when gold content >200g/t
Silver recovery process: silver chloride precipitation conversion rate>98%
Quality control and troubleshooting
Case 1: Dendrite growth of copper cathode
Causes: High concentration of copper ions (>200g/L)/excessive current density
Countermeasures:
Dilute electrolyte to 150g/L
Adjust Dk value to 300A/m².
Add 10ppm thiourea to inhibit dendrites
Case 2: Chlorine escape exceeds the standard
Cause: PH value <1.0 / broken anode coating
Solution:
Automatic alkali replenishment system (PH≥1.5)
Electrode coating repair (coating resistance <0.1Ω-cm²)
Installation of three-stage washing tower (NaOH+NaHSO3 absorption)
Case 3: Decrease in copper cathode purity
Diagnosis: Fe³⁺＞5g/L/Ni²⁺＞3g/L
Treatment Process:
Oxidative precipitation (H2O2 adjusts ORP to 500mV)
Solvent extraction (LIX84-I extractant)
Electrolyte replacement (≤15% old liquid elimination)
Environmental protection and safety technology system
Exhaust gas treatment
Chlorine capture: two-stage alkali absorption (NaOH concentration 20%)
Tail gas emission: Cl₂＜1mg/m³ (GB 16297 standard)
Wastewater recycling
Membrane separation technology: rolled RO membrane (recovery rate>75%)
Evaporation and crystallization: ton of water vapor consumption ≤ 0.8t
Hazardous waste control
Anode mud curing: cement curing (Cu of leaching solution＜0.5mg/L)
Emergency storage: impermeable pool volume ≥ 2 times the maximum tank liquid volume
Technological innovation direction
1. Bipolar membrane electrodialysis technology
Hydrochloric acid regeneration rate>90%
Energy consumption reduced by 35% (compared with the traditional process)
2. Intelligent control system
Online composition analysis (LIBS technology, accuracy ± 0.1g/L)
Digital twin model (deposition thickness prediction error <5%)
3. Green process breakthrough
Oxygen cathode technology: replacing chlorine precipitation reaction, saving 800kWh
of electricity per ton of copper
Biological reductant: replacing chemical oxidizer (COD reduction of 60%)
Industrial Outlook
With the surge in demand for new energy battery recycling and electronic waste treatment,
copper chloride water electrolysis technology has ushered in three major development opportunities:
Fine control: preparation of nano-sized copper powder (particle size D50 <100nm)
System integration: electrolysis-extraction combined process (metal recovery rate>99.5%)
Low-carbon transformation: photovoltaic DC power supply system (carbon footprint reduced by 40%)
It is recommended that production enterprises focus on breakthroughs:
Zero-discharge technology for high-salt wastewater
Multi-metal synergistic extraction program
Intelligent electrode life prediction system
Mastering the dynamic balance law of the electrolysis system and building a database of process
parameters will become the key for enterprises to enhance their core competitiveness. It is expected
that in the next five years, the speed of technology iteration in this field will be increased by 50%,
and enterprises that lay out the innovative technology chain in advance will dominate the
market pattern.