• SEPARATION products
  • Thickener and flocculant plants
  • ANDRITZ thickening and clarification systems

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 diameter coal high rate thickener

ANDRITZ Thickener and clarifier

35m 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.

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

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
  • Sub substantial space available for pumps, piping and maintenance work underneath the thickener
  • Easily replaceable discharge cone

10m diameter iron ore high-rate bolted thickener

35m diameter phosphate tailings high rate thickener with peripheral walkway


Mining & Minerals

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


  • Phosphoric acid  

Find out more ...


ANDRITZ AUTOMATION is a leading supplier of machines and plant control systems with 65 sites worldwide.

Read more

What's your biggest separation challenge?

Ask your separation specialist

Contact us now
Contact us
South Africa
Get in contact
  • ANDRITZ thickening and clarification systems PDF : 1.6 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