Pumps for the recycling industry

Biomass pump


Recycling is a diverse industry with a wide range of applications and requirements. As more and more products are recycled process and techniques are improving and, crucially, so are the number of aggressive and abrasive by-products.

In many cases, the safest and most effective way to deal with these aggressive by-products is by pumping them as slurry. We have range of pumps which perfectly matches this need including centrifugal slurry pumps, flap valve pumps ideal for solids contents and submersible slurry pumps with polyurethane liners which are ideally suited to aggressive applications.

Applications for pumps in the recycling and waste industry

Biomass (AD, Anaerobic Digestion)

Biomas, also known as Anaerobic Digestion, is the use of organic waste to create methane gas with a digestate fertilizer as a by-product of the process. In Biomass, the waste is usually mixed with water to create a slurry, which is then left to decompose in a sealed vessel for around 40 days in which time the methane is formed and collected. During this time, it requires agitating to ensure the most efficient extraction of methane from the waste.

Due to the large and irregular solids contents in the waste, a hard wearing, robust pump is needed both for the initial mixing and the agitating, such as the SlurryPro centrifugal slurry pump. Not only can it handle solids very effectively, but it also has wide internal tolerances meaning that even with significant amounts of wear it still pumps efficiently.

For initial mixing and transporting the waste, pumps like the Audex AW submersible range are often used on these sites due to their large solids capability and built in agitators.

Recycled Aggregates

In a similar process to a conventional quarry, recycled aggregates are created using materials from demolition sites as raw material instead of virgin rock that has been extracted from a quarry. Usually processed through a crusher followed by a wash plant, this recycling process creates silt and small solids laden water that needs to be pumped to extract the full value and return the water to the beginning of the process. Some typical pump applications include:

- Silt underflow
- Clean water feed
- Filter press
- Cyclone feed
- Water recirculation

The SlurryPro (for higher concentrations of solids) and Audex pumps (for sumps and lower solids percentages) excel in the above applications, being hard wearing, long lasting pumps designed to handle aggressive fluids.

Plastic Recycling

Plastic recycling is a complicated process, mainly because the different plastic types that need to be separated have such similar properties. However, the drive to reduce dependence on fossil fuels means that new and innovative methods of separating them are being devised continually.

In plastic recycling, pumps are commonly used in the washing stage, where the crushed/shredded waste is mixed with a cleaning fluid, and during the separating stage, where chemicals are added to the plastic mix to help segregate certain types of plastic. At the end of each process, pumps are also used to recirculate the dirty water back to the beginning to be used again.

The plastic solids contents, plus the other waste and the chemicals added into the process make for a complicated pumping application that the SlurryPro heavy duty pump excel in, due to their long lasting internal components and simplicity of maintenance. 

Metal Recycling

As a valuable commodity that can be recycled endlessly without affecting its properties, metal is widely recycled very effectively. In the metal recycling process, water is widely used and recirculated through various processes – during which it often picks up small abrasive solids and fine metal particles, which leads to an extremely abrasive fluid to be pumped. Some of these processes include:

- Dust suppression/collection
- Washing
- Cooling
- Separating different materials

The SlurryPro (for higher concentrations of solids) and Audex pumps (for sumps and lower solids percentages) excel in the above applications, being hard wearing, long lasting pumps designed to handle aggressive fluids.


Landfill, executed in an old quarry or other similar excavation, usually requires emptying of the residual water before and during its use. Once it is drained, a liner is placed inside to prevent contaminating fluids from seeping into the ground around and then waste is placed on this liner. Common pumps on landfill sites are self-priming centrifugal pumps, such as the Audex AD range, and small submersible pumps, often pneumatically operated. The Audex AD pump range is a proven, hassle free self-priming pump available powered by electric or diesel energy sources, developed with ease of maintenance and customer peace of mind as a key focus. Being mounted on a durable trolley design gives this pump a great flexibility on site while also covering the most frequently needed duty points.

Recycled Process Water

Nearly all industrial recycling plants use water at some stage in the process, usually for applications such as:

- Washing
- Sorting/segregating different types of waste
- Cooling (head exchangers)
- Dust suppression
- As an additive to the main waste, so as to be able to transport it

However, this means that once the water has been separated from the waste at the end of the process it contains normally particles from the waste, such as silt (in aggregate recycling), metal fines (metal recycling), etc – when this fluid is put back into the process it makes it difficult to pump as it is now an abrasive fluid. SlurryPro hard wearing centrifugal pumps, with their heavy duty linings, and Audex submersible pumps are ideal for recovering this fluid as they are designed to handle abrasive fluids efficiently.

(Pictured top: Biffa Horsham)


Case Study: Glasgow Viridor Recycling Centre - Updated Feb 2020

White Paper: Pumps for the Recycling Industry - Don't Waste your Money

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This brochure covers the following:

- Plastic Recycling

- Metal Recycling

- Biomass (AD, Anaerobic Digestion)

- Recycled Process Water

- & much more

Download your FREE copy to learn more.