Key Benefits

  • Durable
  • Easy to maintain
  • Safer operation
  • Customisable configuration

FLSmidth electrowinning is safe, highly efficient and consistent

When electrowinning, it’s essential to have a machine that is safe, highly efficient, and can promise consistent precious metals recovery.

At FLSmidth, our extensive technical expertise ensures that we will have the best solution for your electrowinning needs with our Electrowinning Cells and systems designed for optimal electroextraction.

FLSmidth has over 200 gold and silver electrowinning cell installations worldwide – a testament to our popular stainless-steel body cell renowned for its high-current efficiency and ease of sludge removal. For the last 20+ years, our cells and systems have produced excellent extraction efficiency, are easy to use and require minimal maintenance. There are many reasons our technology has become a trusted product that many companies and end-users choose project after project.

We design our cells and operate them to produce gold and silver sludge on a stainless-steel mesh-wrapped punch-plate cathode. For easy servicing, the cathodes are moved along the buss bar when the cell lid is opened, and the sludge is washed from the mesh and down the sloped bottom to the outlet flange using a pressure sprayer. The sludge is then pumped from the cell to the sludge filter before it is dried and smelted.

Our cells work with all types of precious metal recovery systems, including ZADRA and AARL elution systems, high-grade leaching systems, and intensive cyanidation from gravity systems. Generally used with gold and silver-bearing cyanide solutions, our cells have also been used successfully with non-cyanide metal-bearing solutions.

We offer cell sizes from 50 to 150ft of cathode equivalent volume, normally ranging from 500 to 2000 applied amps per cell, as shown in the table below.


Cell Size 50ft3  75ft3  100ft3  125ft3  150ft3 
 # Anodes  14  20  28  36  45
 # Cathodes  13  18  26  33  42
 Rectifier Amps  750  1,000  1,500  2,000  2,500
 Typical Gold Production per Year, ozt/kg

 30,000 / 975

 40,000 / 1,300  60,000 / 1,950  80,000 / 2,600  105,000 / 3,250
 Maximum Gold + Silver Production per Year, ozt/kg  200,000 / 6,220  300,000 / 9,330  400,000 / 12,440  500,000 / 15,550  600,000 / 18,660
 Typical Carbon Plant Size, tonnes  0.5  1.0  1.5  2+  3+


Each cell is designed to treat 15–80 gallons per minute (3.5–18 m3/hr) of pregnant solution, from very low to very high concentrations of gold and silver. The cells are typically serviced once per week to recover the precious metal sludge from the system. Installations normally operate in the buss bar range of 2.1–5 volts and 60–90 amps per cathode and some high-grade solutions will use higher amperage per cathode. Any fumes generated during electrowinning are removed via the local electrowinning cell exhaust system.

A durable machine designed with safety and versatility in mind

At FLSmidth, we aim to tailor our products to suit your needs. This is no difference when it comes to our Electrowinning Cell, as it is a robust product that comes with a range of options and applications.


Our innovative cell design is built from stainless steel, which makes it more durable and less at risk of catastrophic fire than fibreglass cells. The cell body is lined with polypropylene for electrical isolation and heat insulation.

The stainless-steel anodes and cathodes are less susceptible to corrosion and have extended lifespan.

Easy to maintain

Our Electrowinning Cell is designed for in-cell cathode washing with a portable pressure sprayer or installed spraying system. This reduces the need to remove cathodes for cell servicing and significantly lowers sludge recovery time and cost. 


We also supply cathode wash tanks and cathode lifters for those preferring to remove the cathodes during servicing. 

Safer operation

During the carbon elution and electrowinning process, many harmful gases and vapours may be created. Our Electrowinning Cell comes with a built-in exhaust plenum with outlet flange and a separately supplied exhaust fan/system, to pull the fumes from the cell.

Customisable configuration

Our Electrowinning Cell and systems can be arranged to fit into any existing refinery. Our cells come in different sizes and haves electable left- or right-hand orientation plus vertical or horizontal flanges. The cells are easy to configure during engineering prior to our manufacturing. There are also many optional extras that you can choose to enhance the performance of your electrowinning cell, making it a design that can suit you, regardless of your needs.


Electrowinning Cell options


Hydraulic Actuated Lids

Hydraulic lid actuation with control valve replaces manual opening/closing of lids.


Corrosion Resistant Spray-in Liners

Spray-in corrosion resistant liner for corrosive solutions. Recommended for chloride, sulphate and silicate containing solutions.


Corrosion Resistant Anodes

Carbon and DSA anodes offered for highly corrosive electrowinning solutions.


Direct Connect Electrodes

Electrodes are connected via cabling to common distribution blocks. Use in large systems in conjunction with Mercury Abatement Systems for solutions containing mercury.

Ancillary Equipment

Cell Structural Steel with Operating Platforms, Rectifiers, Cabling, Sludge Filters, Sludge Pumps, High Pressure Sprayers, Exhaust Fans and Duct, Piping and Valves.


Electrowinning Systems options

Mercury Abatement System

Mercury abatement system for treating electrowinning cell exhaust fume containing mercury vapor.


Electrowinning Testing and Circuit Sizing

Electrowinning tests for site-specific solutions to determine electrowinning performance and overall circuit sizing.


Process, Layout and Detail Engineering

Electrowinning System Process, General Arrangement and Detailed Mechanical engineering.


Complete System Engineering

Complete Process, General Arrangement and Detailed Mechanical engineering offered for up and downstream processes. 


Troubleshooting services for system and equipment

Features that promise ease, productivity, and affordability

The features that come with our Electrowinning Cell aim to make your experience a lot easier, more productive, and more affordable.

Flat busbars and electrodes

Flat anode and cathode busbars are positioned at the front of the cell for ease of cleaning.  The contact points of the anodes and cathodes are also flat and held tightly to the busbar during operation by the compression-locked lid. The electrodes may be moved and shifted by simple sliding when the lids are open. 


Sloped bottom

A sloped bottom is used to ensure that the precious metals sludge can be removed easily, as well as to increase sludge capacity.


Lockable lid

Stainless-steel lids are compression locked against the electrodes, pinning the electrodes to the buss bars. End-user locks may be installed on the closures for safety and security.


Basketless cathodes

The cathode mesh is attached directly to the cathode plate rather than being held in place by a basket. This allows for in-cell washing, reducing service time and personnel. Because of this innovative technology, our Electrowinning Cells have been known to minimise service time by up to 75%.


Corrosion-resistant products

Optional equipment that can be offered with our Electrowinning Cell includes a corrosion-resistant spray-in liner – recommended for chloride, sulphate, and silicate containing solutions – and corrosion-resistant anodes, designed for particularly corrosive solutions. They allow for more flexibility when it comes to processing solutions and less of a need for costly water purification systems.

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