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Dimensionally Stable Anodes for Electrowinning & Electrorefining

Ir-Ta MMO and platinized titanium anodes for copper, zinc, nickel and cobalt electrowinning plus electrorefining duties. Stable cell voltage, zero lead contamination of the cathode metal, and documented coating performance — so current efficiency and energy cost stay under control.

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Copper ElectrowinningZinc ElectrowinningNickel & CobaltElectrorefining
0.2–0.6 kA/m²Rated Current Density
5–10 yrsDesign Life at Rating
100%XRF & QC Tested
24hEngineering Response
Molten metal being handled in a metal production plant for electrowinning and electrorefining industries
Engineering Reality

Electrometallurgy Runs on the Anode

Copper, zinc, nickel and cobalt are recovered in tank houses where current is pushed through sulphate electrolyte between insoluble anodes and starting cathodes. For over a century the anode was lead — still true in most zinc and copper plants — and every plant pays for it in cell voltage, energy cost, anode maintenance and lead carry-over into the cathode metal.

DSA®-type mixed metal oxide (MMO) anodes change that equation. An Ir-Ta MMO anode holds a stable oxygen-evolution potential, keeps a constant inter-electrode gap because it does not deform, and releases no lead into the electrolyte — which lowers cell voltage by roughly 0.3–0.5 V in sulphate duty, cuts energy consumption per tonne of metal, and removes the lead contamination concern from cathode quality and environmental compliance at the same time.

Industrial steel plant tank used in metal production and electrolytic tank house operations
The engineering boundary: electrode selection is a current-density and electrolyte decision, not a price decision. Zinc and copper sulphate electrolyte, nickel sulphate/chloride and electrorefining circuits each need a different coating and substrate — we rate every anode to your actual electrolyte composition, temperature, current density and duty cycle before quoting.
The Challenges

What Limits Electrowinning & Electrorefining Performance

Four constraints dominate real tank houses — from copper SX-EW to zinc and nickel plants. Each one is addressable with the right anode and cell design.

🛡

Lead Anode Contamination

Lead-silver anodes shed lead and manganese dioxide into the electrolyte. Lead reports into the cathode metal and into the plant effluent — a metal-quality and environmental burden that tightens every year.

⚡

Cell Voltage & Energy Cost

Lead anode overpotential and the resistive PbO₂ layer on its surface push cell voltage up to 2.0–2.5 V in zinc duty. Electricity is the biggest operating cost in electrowinning — every 0.1 V saved on 1,000,000+ cells-amps means real energy and cost per tonne.

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Anode Maintenance & Downtime

Lead anodes creep, buckle and build oxide scale that must be cleaned and replaced on schedule. Each stripping, straightening or replacement cycle stops the cell line and adds labour, anode stock and handling cost.

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Aggressive Sulphate Electrolyte

CuSO₄/H₂SO₄ and ZnSO₄/H₂SO₄ electrolytes are hot, acidic and hard on any surface. Without a corrosion-resistant, dimensionally stable anode, the gap changes, current distribution drifts, and current efficiency and cathode quality both degrade.

Selection Guide

Choose the Right Anode for Your Tank House

Match your electrolyte and metal duty to the correct coating and format. The table below is the fast path — our engineers refine it with your cell voltage, temperature, current density and cathode quality targets.

ApplicationRecommended AnodeCoatingCurrent DensityTypical LifeKey Benefit
Zinc electrowinning (ZnSO₄ electrolyte)Ir-Ta MMO plate / meshIrO₂/Ta₂O₅0.3–0.6 kA/m²3–8 yrsLower cell voltage, no lead in electrolyte
Copper electrowinning (SX-EW, CuSO₄)Ir-Ta MMO plateIrO₂/Ta₂O₅0.2–0.5 kA/m²3–8 yrsStable gap, clean cathode, less energy
Copper electrorefiningMMO plate / platinized Ti starterIr-Ta / Pt0.2–0.35 kA/m²5–10 yrsDimensional stability, uniform current
Nickel electrowinning (NiSO₄/NiCl₂)Ir-Ta MMO plate / meshIrO₂/Ta₂O₅0.2–0.5 kA/m²3–8 yrsChloride-tolerant coating, low overpotential
Cobalt electrowinning (CoSO₄)Ir-Ta MMO plateIrO₂/Ta₂O₅0.2–0.5 kA/m²3–8 yrsNo lead carry-over into cathode cobalt
Electrolytic manganese (MnSO₄)Ir-Ta MMO plateIrO₂/Ta₂O₅0.3–0.6 kA/m²3–8 yrsStable voltage in high-acid sulphate duty
Media: ZnSO₄/H₂SO₄ · CuSO₄/H₂SO₄ · NiSO₄/NiCl₂ · CoSO₄ · MnSO₄Coating basis: IrO₂/Ta₂O₅ oxygen evolution · Pt hydrogen-side / starter dutySubstrate: ASTM B265 Gr1 / Gr2 titanium
Anode Range

Ehisen Electrometallurgical Electrode Range

Six core titanium electrode formats for zinc, copper, nickel, cobalt and manganese tank houses — each coated and rated to its sulphate electrolyte with traceable material and coating documentation.

Ehisen ruthenium-iridium coated titanium anode plate for zinc and copper electrowinning
Zinc / Copper EW

Ir-Ta MMO Plate Anode

High-stability iridium-tantalum anodes for zinc and copper sulphate duty, rated for stable cell voltage and low overpotential in hot acidic electrolyte.

SubstrateGr1 Ti plate / mesh
CoatingIrO₂/Ta₂O₅
Current density0.2–0.6 kA/m²
Design life3–8 years at rating
Ehisen titanium tube anode for electrorefining and high-current sulphate cells
Electrorefining / High-Current

Titanium Tube & Rod Anodes

Round and tubular Ti anodes for electrorefining circuits and cells where uniform radial current distribution matters.

DiameterΦ16 – Φ60 mm
CoatingIr-Ta / Ru-Ir / Pt
Current density0.2–1 kA/m²
Design life3–10 years
Ehisen MMO and platinized titanium cable and rod anodes for auxiliary electrolytic cells
Auxiliary / Side Cells

MMO Cable & Platinized Rod Anodes

Flexible MMO and platinized titanium anodes for small cells, side reactions and current-carrying auxiliary electrodes in metal winning circuits.

FormatCable · rod · wire
CoatingIr-Ta / Pt
Current density0.2–2 kA/m²
Design life3–10 years
Ehisen mesh tube single piece platinized titanium electrode for electrowinning cells
Mesh Tube

Platinized Titanium Mesh Tube Anode

Single mesh-tube electrodes with high effective surface area for nickel and copper circuits requiring low anode potential.

SubstrateGr1 / Gr2 Ti mesh tube
CoatingPt, 5–20 g/m²
Current density0.2–1 kA/m²
Design life5–10 years
Ehisen mesh tube anode cluster assembly of six platinized titanium electrodes
Cluster Assembly

Mesh Tube Anode Cluster

Six-tube mesh clusters that spread current uniformly across the cathode face — the practical way to scale up winning cells without hot spots.

Configuration2×3 / 1×6 cluster
CoatingPt / Ir-Ta
Cell coverageUp to 1.5 m² per cluster
Design life5–10 years
Pure titanium mesh sample used for cathode blanks and anode substrate in tank houses
Substrate & Hardware

Titanium Mesh, Blanks & Hardware

Pure titanium mesh, cathode blanks and current-distribution hardware machined and welded to your tank house geometry.

MaterialGr1 / Gr2 Ti
Mesh typeExpanded · woven · welded
FinishPassivated / coated on request
Design life10+ years structural
Reference Specifications

Standard Dimensions & Output Data

Factory reference tables for the core electrowinning and electrorefining anode formats. Other sizes and precious-metal loadings can be customised on request.

Ir-Ta MMO Plate Anode (Sulphate EW)Size (mm)Active Area (m²)Current @ 0.4 kA/m² (A)Ir Loading (g/m²)Life (yrs)
Plate 300 × 500300 × 500 × 20.3012010–303–8
Plate 600 × 1200600 × 1200 × 21.4457610–303–8
Mesh 300 × 500300 × 500 × 1.50.3012010–303–8
Mesh 600 × 1200600 × 1200 × 1.51.4457610–303–8
Platinized Titanium Anode (Starter / Side Duty)Pt Loading (g/m²)Current Density (kA/m²)Life (yrs)Application
Mesh / tube / rod5–200.2–2.05–10Refining starter cells · auxiliary anodes
Titanium Tube AnodeDiameter (mm)Active Length (m)CoatingApplication
Tube 16 mm16 ± 0.50.5–2.0Ir-Ta / PtRefining & high-current cells
Tube 32 mm32 ± 0.50.5–2.5Ir-Ta / PtNickel / copper circuits
Tube 60 mm60 ± 0.80.5–3.0Pt / Ir-TaHigh-current cell banks
Titanium base: ASTM B265 Gr1 (plate & mesh) · B863 Gr1 (tube & rod)Gr1 composition: Fe ≤0.20% · C ≤0.08% · N ≤0.03% · H ≤0.02% · O ≤0.18% · Others ≤0.40% · Ti balance
Quality & Documentation

Documented Quality for Tank House Anodes

Every anode ships with traceable substrate, coating and testing records aligned to ISO-style quality management — so plant metallurgists can trust the cell voltage, the lifetime and the audit trail.

ISO 9001

Quality Management

All production runs under a certified quality management system with full batch traceability from titanium substrate to final test.

MTC

Material Certificates

Titanium substrate to ASTM B265 Gr1 / Gr2 with chemical and mechanical traceability.

XRF Data

Coating Verification

Coating thickness and iridium / platinum loading verified per batch — the parameters that actually control cell voltage, electrode lifetime and energy cost in sulphate duty.

ALT Data

Accelerated Life Test

Performance verified per NACE TM0108-2008 at elevated current density in the sulphate electrolyte under rated conditions.

3rd-Party

Independent Testing

Third-party reports available on request for coating thickness, adhesion and precious-metal loading.

Export Docs

Project Documentation

Certificate of conformity, packing list and inspection records prepared for project handover and audits.

MTCCoating ReportXRF DataALT DataInspection RecordCertificate of ConformityPacking List
Accelerated Life Testing

ALT Conditions per NACE TM0108-2008

Lifetime is verified by accelerated life testing — not field wait. We test at elevated current density in the sulphate media your tank house actually runs, then convert the data to your operating rating.

Coating SystemMediumCurrent Density (A/m²)Temperature (°C)
Ir-Ta MMOZnSO₄ / H₂SO₄ (zinc EW)20,00040 ± 5
Ir-Ta MMOCuSO₄ / H₂SO₄ (copper EW)20,00040 ± 5
Pt10% H₂SO₄ + Cl⁻40,00025 ± 5
Performance

Specs That Keep Tank Houses Producing

0.2–0.6 kA/m²

Rated Current Density

Sustains efficient oxygen evolution in zinc, copper, nickel and cobalt sulphate duty without accelerated coating wear or voltage drift.

0.3–0.5 V

Cell Voltage Saving

Lower anode overpotential versus lead anodes — the saving that cuts kWh per tonne and total plant energy cost.

<3%

Coating Loading Tolerance

Controlled precious-metal loading per batch keeps overpotential, efficiency and lifetime consistent across the whole cell line.

10–30 g/m²

Iridium Loading

Ir loading verified per batch — the loading level is what actually controls anode lifetime and the iridium cost inside your tank house.

FAQ

Frequently Asked Questions About Tank House Anodes

Why replace lead anodes with MMO anodes in electrowinning?
Lead-silver anodes are the historical standard in zinc and copper electrowinning, but they carry three costs: lead dissolves into the electrolyte and reports into the cathode metal, the resistive oxide layer pushes up cell voltage, and the anodes creep and need regular cleaning and replacement. MMO anodes hold a stable oxygen-evolution potential, keep a constant electrode gap because they do not deform, and release no lead — lowering cell voltage and energy cost while removing the lead contamination concern from metal quality and environmental compliance.
What is the difference between lead anodes and MMO titanium anodes?
Lead anodes are made of lead alloy with a PbO₂ surface layer formed in service. They are cheap to buy but deform, scale up and release lead into the electrolyte. MMO titanium anodes use a titanium substrate coated with mixed metal oxides (IrO₂/Ta₂O₅ or RuO₂/IrO₂). They are dimensionally stable, release no metal into the bath and hold a lower, more stable anode potential — the trade-off is a higher first cost that is recovered through energy savings, longer life and cleaner cathode quality.
How much cell voltage can MMO anodes save in zinc electrowinning?
Typical savings are 0.3–0.5 V per cell compared with lead anodes in sulphate duty, depending on electrolyte, temperature, current density and anode age. On a zinc plant this translates into real kWh per tonne of metal saved — across thousands of cells the energy cost reduction is substantial. The exact number comes from an engineering review of your cell data, not from a generic table.
Will MMO anodes contaminate my cathode copper or zinc?
No. MMO anodes release no lead, silver or manganese into the electrolyte. Cathode purity is controlled by electrolyte purification and current density as before, but the anode contribution to metal contamination is removed entirely — a significant advantage for high-spec cathode grades and for plants facing tighter environmental discharge limits on lead.
How long do MMO anodes last at rated current density?
At the rated current density, design life is typically 3–8 years for Ir-Ta MMO coatings in sulphate electrowinning duty, depending on current density, temperature, electrolyte impurity levels and operating profile. We verify performance with accelerated life testing per NACE TM0108-2008 in the actual electrolyte and provide the data with your order.
Can MMO anodes be used in copper SX-EW plants?
Yes. Ir-Ta MMO anodes are proven in copper sulphate/high-acid SX-EW electrolyte. The main considerations are current density, temperature and the manganese levels in the electrolyte, which can deposit MnO₂ on any anode surface. We size the coating and loading to your electrolyte chemistry so the anode keeps a stable potential without premature wear.
What about chloride in nickel electrowinning electrolyte?
Nickel circuits often run sulphate/chloride mixes, and chloride is aggressive to many anode surfaces. Ir-Ta MMO coatings with the correct formulation tolerate the chloride levels found in industrial nickel winning, and platinized titanium is used where the duty requires it. We rate the coating specifically to your electrolyte — chloride content is a defining input, not an afterthought.
Why does anode dimensional stability matter?
The inter-electrode gap between anode and cathode controls current distribution and cell resistance. Lead anodes creep, bow and scale in service, so the gap drifts and current concentrates on some cathode areas — degrading cathode quality and current efficiency. MMO titanium anodes keep their geometry for the full life, so the gap stays constant and current distribution stays uniform from commissioning to retirement.
How do I ensure sample quality matches bulk production?
At Ehisen, consistency is controlled by a fixed coating formulation (no random adjustment), the same production line for samples and bulk, controlled coating loading tolerance, batch traceability (LOT tracking) and process records (temperature, cycles, coating passes). The real difference between suppliers is not sample quality — it is whether bulk production can reproduce the same result.
Do you provide accelerated life test data for tank house applications?
Yes. ALT is performed per NACE TM0108-2008 at elevated current density in the sulphate electrolyte of your application, and the data is shipped with the order. This is the objective basis for the design life quoted on your coating — not a marketing figure.
What is the lead time for tank house anode orders?
Standard production typically ships in 2–4 weeks depending on format, coating and quantity; custom geometry and precious-metal loadings extend this slightly. We confirm a firm schedule with your order and update you from coating to packing list.
How do I size anodes for my electrowinning cell line?
Anode area follows from your required cell current divided by the rated current density of the coating, with allowance for coating deactivation over the design life and the operating duty. Send us the cell current, electrolyte composition, temperature, target current density, cathode geometry and number of cells — we will calculate the anode count, size and loading for you within 24 hours.

Need the Right Anode for Your Tank House?

Send us your cell details — metal, electrolyte composition, current density, cell dimensions and target lifetime — and our engineers will recommend the correct coating, anode format and quantity within 24 hours.

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Related Applications

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Tank House Anatomy

The Components of an Electrowinning Cell House

Reliable metal production is a system result — cell, electrodes, electrolyte circulation, power supply, cathode handling and gas management must work together. Ehisen supplies the coated electrodes at the heart of the current path.

01

Electrolytic Cell & Busbar

The repeating cell unit where DC current deposits metal on the cathode. Cell geometry, electrode spacing and busbar sizing control current efficiency and energy use.

02

Anodes & Cathode Blanks

The current-discharging elements — Ir-Ta MMO or platinized titanium anodes in plate, mesh or tube format, paired with titanium or stainless cathode blanks rated to the electrolyte.

03

Electrolyte Circulation

Sulphate electrolyte is pumped, filtered and heated at controlled flow and temperature. Feed purity and temperature directly control coating life and deposit quality.

04

Rectifier & Power Feed

Rectifiers convert AC to stable, low-ripple DC cell current. Clean current keeps electrodes efficient and extends coating life.

05

Cathode Stripping & Handling

Deposited metal is stripped, washed and weighed on schedule. Consistent stripping cycles protect the cathode blanks and the anode gap setting.

06

Gas Collection & Ventilation

Oxygen (and trace acid mist) is captured above the cells and scrubbed. Good ventilation protects both personnel and the electrical busbar system.

Project Sequence

From Cell Requirements to Installed Anodes

Building or retrofitting a tank house follows a proven four-stage sequence. Ehisen supports you at every stage with engineering input and documented hardware.

Step 1

Cell Line Analysis

Electrolyte composition, temperature, cell current, current density, duty profile and target cathode quality are reviewed, then anode format, coating and precious-metal loading are calculated.

Step 2

Engineering & Sample

We recommend the coating system and can supply sample anodes for testing in your actual electrolyte before full production.

Step 3

Fabrication & QC

Anodes are manufactured with batch traceability, coating inspection and accelerated life testing, with full process records shipped alongside.

Step 4

Installation & Trial Run

Anodes and blanks are positioned, contact resistance verified, and cell voltage and cathode quality checked during the trial run until performance is stable.

Engineering tips: keep anode-to-cathode spacing and electrolyte flow consistent across the cell — uneven spacing concentrates current and accelerates coating wear. Control electrolyte temperature and impurity levels, and always record cell voltage and current efficiency against metal output to prove tank house consistency before accepting a new cell line.
Why Ehisen

A Manufacturing Partner, Not Just an Anode Supplier

Tank house buyers choose Ehisen because coating consistency, traceability and engineering response decide how long an electrowinning anode really lasts — not just the catalogue price.

In-House Line

Controlled Coating

Coating applied on our own production line with a fixed formulation and controlled loading tolerance — samples and bulk runs are made to the same standard.

LOT Tracking

Full Traceability

Every batch carries a LOT number linking substrate material, coating process records, inspection results and shipping documents.

ALT Lab

Life-Test Verified

Accelerated life testing per NACE TM0108-2008 at 20,000 A/m² in sulphate media converts laboratory hours into your tank house rating.

Free Design Help

Engineering Support

Our engineers review your electrolyte, current density, temperature and cell geometry, then recommend coating, format and loading — within 24 hours.

40+ Countries

Global Logistics

Export experience across 40+ countries with complete documentation: MTC, coating reports, XRF data, inspection records, certificate of conformity.

On-Time

Reliable Delivery

Production planned against your project schedule, with order status updates from coating to packing list.

How We Work

From Your Enquiry to Delivered Anodes

A clear, three-step process keeps every tank house order on specification and on schedule.

1

Send Requirements

Share your metal, electrolyte composition, current density and target coating loading via WhatsApp or email — or send a cell drawing and we will extract the parameters.

2

Engineering Review

Within 24 hours you receive a recommendation: anode coating, format, dimensions, loading and the supporting calculation basis.

3

Fabrication & Shipment

After approval, production runs with batch QC, then ships with the full document pack: MTC, coating report, XRF and ALT data and packing list.

Our commitment: every tank house anode order includes a standard 12-month warranty against coating defects, plus the design-life test data that supports your cell line programme. If the delivered material does not match the agreed specification, we replace it at our cost.

Get in Touch

Send us a message if you have any questions or request a quote. We will be back to you ASAP!