EKATO in Hydrometallurgy

Reliability and Process Know-How

The extraction of metals using hydrometallurgical processes is gaining more and more importance. In contrast to pyrometallurgy, hydrometallurgical methods are still economically viable for extracting complex types of ore with low metal contents that are being mined increasingly frequently.



 EKATO’s product and service portfolio include:

EKATO is the world leader for autoclave agitation technology. EKATO offers customized solutions and has valuable experience in autoclave applications worldwide.

Our services are covering a wide range such as lab testing, CFD and FEA studies, design and manufacturing of agitators and site assistance.

EKATO offers a robust mechanical design and high quality manufacturing (titanium clean room for welding). Through our seal division we offer a complete range of mechanical sealing solutions and seal support systems for  autoclave trains.

Autoclave technology is used in hydrometallurgy when extraction by classical atmospheric leaching methods is not economical.

Autoclaves are typically horizontal vessels divided into 3 to 9 compartments or a series of single cascading vessels working at high temperature and high pressure. Extreme temperatures as well as fluctuating pressure regimes require sound designs and best quality products, ensuring maximum availability and lifetime.

The chemical reaction rate is the highest in the first compartments so the design of the agitators both in process and mechanical terms is crucial for the success of the operation. Perfect mixing of feed streams (slurry, oxygen, acid or steam) in an asymmetrical geometry must be ensured. 


Among the different applications there are mainly two autoclave types:

  HPAL (High Pressure Acid Leach) POX (Pressure Oxidation)
Operating data 45-55 bar / 240 – 260 °C 20-35 bar / 190 – 230 °C
Materials Titanium Grade 12 Titanium Grades 2, 5, 12

super duplex
Abrasion Moderate High
Mixing duties Fast dispersion of feed streams

Optimal blending of acid and slurry

Solid suspension
Gas dispersion / Mass transfer

Solid suspension

Heat transfer
EKATO solutions Feed pipe location optimization (laboratory testing – CFD simulations)

Optimized solid suspension with
EPAL impeller

EPAL-R abrasion reduced impeller

Abrasion resistant special coatings

High Pressure Seal ESD 64H

Automatic Seal Supply System AVS
Optimized blade geometry reducing abrasion with
EPOX-R impeller

EPOX-C impeller (ceramic blades)

Abrasion resistant special coatings

High Pressure Seal ESD 64H

Automatic Seal Supply System AVS

Stirred tank reactors under continuous atmospheric operating conditions fulfill an important key function for many gassed hydrometallurgical leaching processes such as:

  • Bioleaching reactors
  • Direct leaching
  • Pre-oxidation tanks
  • Cyanide detoxification
  • Arsenic removal
  • Iron precipitation
  • Gassed chloride leach, e.g. for the nickel matte processing
  • Recovery of Scandium and rare earth elements (with SO2 gas)
  • Production of battery-grade lithium carbonate (with CO2 gas)

Apart from realizing “economies of scale” and implementing advances in process performance, achieving a cost optimization of such systems is a fundamental goal. Therefore EKATO has developed proprietary and unique gassing solutions the EKATO COMBIJET and EKATO COMBIJET PLUS.

These technologies have been successfully implemented and provide the following advantages compared to other technologies:

  1. Superior gas dispersion and high pumping rate for solids suspension providing improved yields and more stable hydrometallurgical process results.
  2. Higher gas utilization for reducing the costs for air compressors or lowering expenses for pure industrial gasses, such as oxygen, sulfur dioxide, chloride gas or carbon dioxide.
  3. Very stable mixing even at very high gassing rates avoiding unnecessary overdesigns of agitator equipment.

Since the quality of ore bodies often decreases as rich resources get depleted, one trend is to process more slurry volume in one plant or module which leads to further increased vessel sizes for current and future projects. These units have to be reliably designed to ensure that the whole plant can be reliably operated. Mixing tasks can be from solids suspension duties to demanding blending of non-Newtonian slurries, if for example increased solids concentrations have to be handled. 

Typical applications are:

  • Leach tanks (CIL, CIP)
  • Blending of non-Newtonian slurries with increased solids concentrations, e.g. autoclave feed tanks and slurry pipeline tanks
  • Repulp /  conditioning tanks, e.g. CCD interstage mixers, filter feed tanks,…
  • Storage and surge tanks

As an agitator manufacturer committed to process technology development we make use of the resources in our well-equipped technical center and its experienced process engineers dedicated to the industry. Our capabilities are not limited to our technical center with test pits up to 100 m³ volume.

Additional services include technical reviews of equipment or operations which influence the process performance as for example feed locations. Other options are consultancy services or test programs on site.

A multitude of customers have already found the benefits that optimization of their proprietary production processes delivers by conducting engineering studies with EKATO R&D and implementing the recommendations. Simulation technologies such as CFD (Computational Fluid Dynamics) or FEA (Finite Element Analysis) which are gaining in importance are provided by EKATO’s experienced in-house engineering department.

Special Hydrometallurgical Impellers


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