ANDRITZ thickening and clarification systems

In the most challenging applications, reliable liquid clarification and slurry recovery is critical to maintaining continuous production. This is why ANDRITZ has put decades of expertise into thickening and clarification systems to provide an efficient and cost-effective solution.

Coal high rate thickener

20m in diameter coal high rate thickener

ANDRITZ Thickener and clarifier

35m in diameter Pb/Zn tailings - High rate bolted thickener

ANDRITZ thickening and clarification solutions are designed to achieve the highest production rates without compromising efficiency. For all counter-current decantation (CCD) plants: The new and improved ANDRITZ inter-stage mixing and dilution system for CCD circuits helps to reduce the footprint and consequently cut CAPEX while maintaining low operating costs. The innovative paste-thickener design facilitates highly clarified liquid recovery as well as maximum underflow densities.

ANDRITZ‘s supply philosophy is to present the user with the most effective and technically viable system. This is especially important when very high underflow densities are required. In cases like this, high-density or paste thickening technology can be used in combination with the various filtration technologies offered by ANDRITZ.

A targeted range to meet your requirements

The ANDRITZ thickener range has been designed to meet your needs and constraints in the mining, minerals, and chemical industries.

  • ANDRITZ EcoSET thickener
  • ANDRITZ GeoSET thickener
  • ANDRITZ LiKOSET thickener
  • Mixing and counter-current decantation (CCD)
  • ANDRITZ deep-cone settler
  • Paste technology
  • Custom ANDRITZ thickeners

Discover all our range in details in our ANDRITZ thickening and clarification systems brochure available for download here.

Your benefits

  • High throughput with optimized underflow density, flocculant consumption and overflow clarity
  • Reduced downtime due to innovative feedwell design
  • Global manufacturing facilities
  • Global testing facilities
  • Minimal site construction work thanks to hybrid bolted design
  • Global service centers

Evenflow feedwell 2.0

The benefits of the new and improved Evenflow feedwell are plain to see:

  • Optimum flocculant consumption by enhancing residence time within the feedwell
  • Controlled slurry distribution within the feedwell by incorporating fins to prolong flocculant contact time
  • Low operating costs
  • Elimination of choking by including a deflector plate scraper and clover outlets
  • Reduced downtime for maintenance work

Optimized settling rate with efficient dilution system 

Dilution means to reduce the concentration of solute in a solution by simply adding more solvent.​ This dilution step guarantees a perfect solid-liquid ratio in the feed to enhance settling rate once flocculants are added. Flocculants are more effective once added to perfect solid-liquid ratio. 

ANDRITZ dilution system GR 

  • Internal dilution system​ 
  • Flow rate: 0 – 2,600 m3/hr​ 
  • Situated at a distance that will not hinder free settling rate or mud bed formation​ 
  • Easily Retrofittable​ 

ANDRITZ dilution system NT 

  • Internal dilution system​
  • Flow rate: 600 – 9,000 m3/hr ​ 
  • Use overflow liquid to dilute incoming slurry to the required solid-liquid ratio​ 
  • Can accommodate slurries with low pH values​ 

ANDRITZ dilution system XT​ 

  • External dilution system​ 
  • Flow rate: 2,800 – 15,000 m3/hr​
  • Allows for large dilution rates​ 
  • Better mixing capabilities​ 

Overview of Evenflow feedwell 2.0

Cross-section of Evenflow feedwell 2.0

Paste and Counter-Current Decantation (CCD) technology

Mixing and counter-current decantation

  • CCD dilution pump/mixers allowing flat design and elimination of elevation differences between CCD thickeners
  • Maximized soluble recovery thanks to inter-stage mixing
  • High levels of closed-circuit dilution counteract the negative effects of surging underflow pumps
  • Bulk closed-circuit dilution technology (35% to 5% solids) using thickener overflow taken from the overflow weirs
  • Accurate (to within 1%) and adjustable feed dilution to optimize flocculant usage


  • The optimum percentage of feed solids will ensure maximum flocculation and optimized solids loading (t/m²/day)

  • Consistent underflow quality

  • Efficient washing in CCD circuits

Paste technology

  • Good mixing to assist in agglomerating many individual flocculants, which can release trapped liquor when compressed
  • Feed distribution systems that introduce the flocculated material into a consolidated bed where new material interacts with old to further grow the flocculated material
  • Picket fence rakes to assist with water release from the compacting sludge
  • Low-profile rake designs that allow the easy release of water and minimize flocculated solids hang-up

ANDRITZ bolted thickener

  • Shorter assembly time on site
  • Easier / less complex assembly
  • No non-destructive testing required on site welds
  • Minimal paint touch-up required on site
  • Less weather-dependent during site erection (due to shorter assembly time and less paintwork)
  • Light construction compared to other bolted thickeners in the industry
  • Complies with all major national and international standards on safety and construction work
  • Possible assembly in our workshop prior to delivery to ensure a smooth installation on customer site
  • Substantial space available for pumps, piping and maintenance work underneath the thickener
  • Easily replaceable discharge cone

18m diameter iron ore high-rate bolted thickener


Mining & Minerals

  • Copper/cobalt
  • Uranium
  • Coal
  • Lead
  • Zinc
  • Iron ore
  • Industrial effluents
  • Clarifying of underground mud
  • Lithium
  • Potash
  • Phosphate


  • Phosphoric acid  

Find out more ...

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  • Recovery of highly clarified liquid

    ANDRITZ thickening and clarification systems

    PDF : 2.6 MB
  • Separation expertise for your success in the mining and minerals industry PDF : 2.8 MB
  • Solutions you can count on in the chemicals industry PDF : 3.1 MB