Veolia Closed-Loop Glass Recycling Facility, St Helens, Merseyside, United States of America

mineral wool insulation

Veolia in association with Knauf Insulation has launched the construction of a closed-loop glass recycling facility. The new facility will be built on land owned by Knauf next to its production facility in St Helens, Merseyside, UK.

The recycling plant will source glass from material recovery facilities across the UK, including those owned by Veolia, to produce high-quality cullet. Knauf will use the cullet to manufacture its insulation products.

Construction of the facility is being undertaken at a cost of £10m ($10.79m) and will be completed by the end of 2017. The project is expected to generate 18 permanent jobs in the region.

Veolia closed-loop recycling facility details

The new facility will be housed in an existing building located on a 1.3ha site. A number of modifications will be made to the building to enable recycling operations.

A new glass-tipping area with a height of 10.67m and a clad extension will be constructed towards the southern end of the building. An insulated roof will also be built to reduce noise levels.

The building will include a loading area, processing area and ancillary equipment for the treatment of glass. It will also include a dust extraction system and stack associated with the glass drying process.

A weighbridge and refurbished welfare block will also be part of the facility.

Processing of glass at the new Veolia plant

The St Helens facility will process 80,000t-120,000t of separated glass, which will be hauled by articulated bulkers. Glass will be transferred into the glass tipping area onto indoor storage, which has a capacity of 850t-950t.

Glass will be sorted in three main steps including pre-sorting, de-labelling and optical sorting.

A hopper will transfer glass from the storage area onto a magnet, which will remove any ferrous material. Larger glass material will be sent through a picking cabin, where workers will remove large contaminants manually.

Glass will then move through an eddy current separator to remove non-ferrous material. Smaller material will directly move through the eddy current separator.

The next step will include drying, which will use reduce the moisture content of the glass to 1%. Glass will go through de-labelling, after drying. Friction will be used to remove labels from the glass.

"Friction will be used to remove labels from the glass."

Air separation is then carried out to remove any light material from the glass stream. Non-inert material will be extracted using air knives, zig-zag separators and other types of separators.

The final stage of processing is optical sorting, where non-glass materials such as plastic will be separated using optical sorters. The recovered glass is then crushed into smaller fragments (cullet) and supplied to Knauf. Very small fragments of glass will be stored separately as they cannot be optically sorted.

Knauf will feed the cullet into a furnace, which is melted to convert into glass mineral wool used for manufacturing of insulation products.

Benefits of the closed-loop recycling facility

The St Helens facility will part of Knauf's sustainability goals and provides the company with secure supply of insulation material. It will also save raw materials by replacing the need to use virgin material from quarries.

Furthermore, it will divert waste from landfill and reduce energy demand and carbon emissions. The process technology used for manufacturing mineral wool insulation from cullet uses lower energy, when compared with traditional methods.