AAL Recycling, United Kingdom – Case Study

Posted on: 23 May 2022

AAL Recycling Limited (AAL), United Kingdom, started more than 30 years ago as a one-man, one-truck, one-excavator company. Established in 1992, it is now one of the largest demolition, hauling, recycling and excavation companies in Jersey and the Channel Islands, employing more than 85 people and with a fleet of more than 70 vehicles.

Currently, AAL operates the island’s commercial and household construction waste recycling centre in La Collette, supporting the island’s sustainability project in every way possible. The demolition and excavation area has had the company’s fastest growth, thanks to managing some of the most complex projects developed on the island in recent times.

Given the great growth of AAL Recycling, its owner, Alan Langlois, approached Matec Industries in order to find innovative and technological solutions that would allow processing up to 150 tons/h of recycled material, with water consumption of less than 25 m3/h.

The plant would have to comply with all current regulations, ensuring low energy consumption, and maintaining a high washing and sorting performance of the processed material.
The complete plant consists of the following modules:

Wastewater Treatment and Filter Press
Washing and selection

Wastewater Treatment & Filter Press

To ensure that more than 95 percent of water used during washing and sand sorting was recycled, a complete wastewater treatment and filtration plant was installed.

Let’s take a brief look at the main functions:
From the collection tank, turbid water is pumped into the decanter through the stainless-steel piping via the use of a centrifugal pump.
The flocculating polyelectrolyte solution is injected into the feed line of the settler and reacts with the suspended solids in the liquid, speeding up the natural sedimentation of the mud particles.
The turbid waters arrive in the vertical decanter where the reaction of the polyelectrolyte takes place, aggregating the sludge particles and causing them to precipitate. The clarified waters free of suspended solids then rise to the top of the decanter and by weir and are collected in the perimeter channel located at the top of the decanter it is then conveyed to a stainless-steel clean water tank. At this point it is ready to be reused in the production cycle again through the clean water relaunch pump.
The sludge, meanwhile, settles inside the cone and is discharged once it reaches the required consistency by the opening of the automatic valve.
It is sent to the homogenizer tank below where it is kept in slow agitation. At this point it is ready to be fed into the filter press.

TheMATEC plate filter pressis an industrial machine designed to achieve the best results in dewatering industrial or civil fluids (often referred to as sludge).
MATEC filter presses are designed for use with High Pressure Technology (HPT), capable of working at both operating pressures common to all filter presses and at higher pressures.

The wastewater treatment and filter press module consist of:

Filter press 1500×1500, 170 TT Plates
BIFANG – sludge homogenization tank 100,000 litres
Static Vertical Decanter 220,000 litres
Clean water pump 6,000 LPM
Clean water tank 100,000 litres
Clean water tank 40,000 litres
BIFLOC – Automatic flocculant management system
Centrifugal pump for loading Vertical Decanter 6,000 LPM
Dirty Water Tank 50,000 litres

Washing & Screening

For the washing, grading, and drying the product, the following machines were selected:

AGGRETEC 150

Aggretec is Matec’s rapid installation modular washing and sorting plant ideal for a wide range of sectors, including aggregates, recycling, reclamation and mining. Being a semi-mobile system, it is easily transportable making it ideal for working on construction and demolition sites.

3 Conveyor belts (0-2mm, 2-4mm, 25-40mm)
Sand recovery unit with hydrocyclones
3 Deck vibrating screens
Magnetic belt separator
Feeder screen
Loading Hopper

SCRUBTEC LW-080-500

The combination of intense cleaning action and removal of light contaminants makes the SCRUBTEC a key component in construction and demolition waste recycling systems. It is also ideal for aggregates and mined materials with high clay content.

The material is rubbed through inclined paddles arranged in series inside the machine. These paddles slow down the material feed when it is very dirty, but ease the feed when it is cleaner. The entire washer is coated with an interchangeable wear-resistant steel armour.

Log wash
Impurity screen
Dryer/finishing screen
3 Conveyor belts (16-25mm, 10-16mm, 4-10mm)
Pre-Screening

CONCLUSIONS

Thanks to the technological solutions of MATEC, today AAL Recycling can process up to 150 tons/h of recycled material with a water consumption of only 25m3/h.

With the achievement of these goals and the expectations of Alan Langlois (CEO, AAL Recycling) fulfilled, we can only be satisfied with the results achieved.