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Save water and maximise productivity – thickeners and clarifiers

Whether your goal is maximising solids recovery, or minimising water waste – or both – we have the expertise and equipment to support you. Our range of thickeners and clarifiers optimise solid-liquid separation to help you achieve low total cost of ownership, maximum uptime and increased productivity.

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Key benefits of thickeners and clarifiers

  • Optimised underflow density for solid-liquid separation

    Thickeners work on the operating principles of gravity and particle interactions, with solids settling downwards and liquids rising to the top as they separate. Whether you choose a High-Rate Thickener, a Deep Cone Thickener or one of our other solutions, we'll utilise all our process and materials expertise to optimise the underflow to meet your needs and achieve solid-liquid separation at the desired density, clarity and rate.

  • Exceptional overflow clarity enables enhanced water recovery

    Conserving water resources is a critical element of sustainable mining, and clarifiers have a significant role to play in the recovery, reuse and recycling of water in the mine. With over a 100 years’ experience in the field, we have the knowledge and expertise to deliver overflow clarity, whatever your application and flow requirements. Our focus on maintaining a low total cost of ownership also ensures a robust, durable design and economical operations.

  • Opportunities to enhance thickener performance with upgrades

    Thickeners are long-lived, but just because you have an older model doesn’t mean you can’t improve its performance. The E-volute™ feedwell and E-DUC® or P-DUC feed dilution systems can be retrofitted to existing thickeners to maximise solids throughput, increase flocculant efficiency and optimise underflow solids.

High-rate thickeners 

High-rate thickeners are designed to provide roughly 12 times the throughput of conventional machines of similar size. The key features for high-capacity thickeners are the feedwell design and the feed slurry dilution method. Our patented E-Volute™ feedwell offers Computational Fluid Dynamics (CFD)- optimised energy dissipation and solids distribution. E-DUC® and P-DUC feed-dilution systems maximise flocculation efficiency and settling rates.

Standard thickeners 

Standard bridge-supported high-rate thickener designs are available for accelerated delivery and include either welded or bolted elevated steel tank designs up to 40 m in diameter and are ideal for many applications.

Traction thickeners 

Typically installed in concrete tanks, traction thickeners have a stationary centre pier which supports the rake mechanism central bearing about which the rake arms rotate. The centre pier also supports the rotating feedwell and partially supports the rake mechanism and access bridge. The bridge supports the feed pipe or feed open launder.  At the tank perimeter, the full-radius rake arm is supported on and driven by the drive unit (tractor). The drive unit runs steel traction wheels on a steel rail at the edge of the tank. Under appropriate climatic conditions, traction thickeners are an efficient, cost-effective design.

Bridge-supported and column-supported thickeners 

EIMCO® and Dorr-Oliver®  thickeners are available in both bridge-supported and column-supported designs. We offer beam- or truss-type bridges, depending on thickener diameter. In the bridge-supported design, suitable for thickeners up to 50 m in diameter, the drive is supported by the bridge, driving the rakes with a centre shaft. Column-supported design drives are supported by a stationary centre column of steel or concrete and are practical for thickeners up to 135 m in diameter.

Deep Cone™ thickeners 

EIMCO Deep Cone thickeners produce underflows concentrated to near their limit of pumpability. The deep tank design maximises pulp concentration, and produces uniform, non-segregating underflow slurry with a paste consistency.

Spiral Rake Blade for thickeners: the optimal design

E-Cat® Ultra High-Rate Clarifiers and Thickeners 

With its rakeless design, the E-Cat uses novel technology to accomplish both clarification and thickening in a single unit that takes up minimal area. The design advantages include: 

  • Low capital cost compared to conventional thickeners 
  • Low maintenance costs due to no moving parts 
  • Much smaller area required compared to conventional thickeners 
  • Low operating costs, low flocculant consumption

High-density thickeners 

By adding depth and torque to a high-rate design, high-density thickeners improve underflow densities at a substantially lower cost than deep cone thickeners.

Inclined plate thickeners/clarifiers 

Inclined plate clarifiers maximise the clarifier’s settling area while minimising the tank footprint. To increase the clarification area of conventional clarifiers, we offer inclined plate clarifiers for a range of tank sizes. These inclined plates are constructed in rectangular packs that operate on the same settling principles as the Delta-Stak® clarifier.

Reactor-Clarifier™ solids-contact unit 

EIMCO Reactor-Clarifiers offer optimal flocculation, solids contact and precipitation. Dual concentric rake and turbine drives provide solids raking, along with low shear pumping and mixing.

Delta-Stak clarifiers 

EIMCO Delta-Stak clarifiers combine the simplicity of gravity settling with inclined-plate sedimentation principles. Our patented design reduces space requirements and costs, while providing operational simplicity and high overflow rates.

Hydroseparators 

By increasing the rise rate in thickeners by ‘undersizng’ then we are able to separate particles on solids density differences to allow for lower density particles to flow into the external slope launder.

The addition of concentric elutriation piping on the floor of these units allows for an even higher rise rate and can be used to have a size separation between underflow & overflow.

Add-ons

With its patent-pending, advanced involute design, E-Volute evenly distributes feed within the thickener and minimises flocculant shearing. 

Where wide variations in flow or weight percent solids content are expected, the P-DUC can ensure consistent, optimal dilution level. 

The spiral design of our thickener rake arm assembly reduces energy consumption, minimises downtime and enhances water recovery. 

Maintenance & Service of thickeners and clarifiers

Thickeners will be in the field for decades, but sedimentary technology is constantly advancing. Our designers combine years of engineering expertise with major refurbishments, upgrades, and retrofits for existing machinery to ensure ongoing integrity, reliability and productivity. We can evaluate your thickening and clarification needs, and offer upgrades or retrofits, including completely new mechanisms, feed system retrofits and new drives. Our technical services include: 

  • Product review and improvement

  • Lifecycle analysis

  • Equipment audits

  • Process audits

  • Testing

  • Repairs and refurbishments

  • Upgrades

  • Original OEM parts

  • Retrofits 

Downloads for thickeners and clarifiers

Frequently asked questions

FAQs for thickeners and clarifiers

Clarification and thickening are both solid-liquid separation processes. The clarifier, as its name suggests, focuses on clarifying water for reuse and recycling and to minimise contaminants going into the environment. Thickeners are focused on separating out water – which can be reused – from solids, usually tailings, which may have another useful life or may be stored or back-filled into mined land. 

The main difference between a thickener and a clarifier is in the job they are used for. Thickeners are used to thicken solids – i.e. by removing the water – whereas clarifiers are used to clarify liquids – i.e. by removing low levels of solids. 

Thickening in mineral processing is the act of removing water from solids – called solid-liquid separation. 

Paste thickeners are applicable to applications that require a high level of dewatering. 

High-density thickeners have a deeper sidewall and increased torque to improve underflow densities at a lower cost. 

FLS offers three main types of clarifiers: conventional clarifiers, EIMCO Reactor-Clarifier™ solids-contact unit, inclined plate clarifiers and EIMCO Delta-Stak® clarifiers. 

Our range of thickeners includes the world's largest and highest capacity bridge and column mounted thickeners, High-rate and standard thickeners, High-density thickeners, Deep cone paste thickeners and Traction thickeners. 

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