In 1998 Leicester City Council undertook a comprehensive review of its waste management service. As a result of this review the council developed its waste strategy for the collection, treatment and disposal of the city's household waste for the next 25 years.Their approach has been to develop a new fully integrated waste management service, whereby the collection, treatment and disposal of waste will be linked by a single contract.

In November 2002 Biffa Waste Services was selected as the council's preferred bidder for the contract. In May 2003 building started on waste reception/ recycling and composting centres - supported by the Government's Private Finance Initiative (PFI). It is predicted that the City Council’s MSW recycling rate will hit 40% by the end 2005/2006.

The 'Ball Mill' Recycling Process

All the household refuse that has not been separately collected for recycling is taken to the recycling centre's 'ball mill’. The waste is fed into a 6.4 metre (21 foot) diameter drum (rather like a huge washing machine drum) containing a large number of 5.5 kilogram (12lb) steel balls. As the drum slowly rotates the balls crush and break down the waste to small pieces. Paper together with plastics, and other packaging is broken into small pieces. These can then be separated from the other materials.This material is taken
off site and used by other companies as a fuel.

Any metals including tin cans are crushed flat. Steel is separated from the other wastes by magnets and aluminium is separated by an “eddycurrent” (a non-ferrous metal)
separator. Both are also sent off site for recycling.

Food waste, garden waste and other similar materials are also treated in the ball mill.This "organic" waste material is broken into smaller pieces and is then sieved out for transfer to enclosed containers and taken to the nearby anaerobic digester.

The remainder consists of broken bottles, stones and other heavy items. At present there is little that can be done with these materials so they are sent to landfill. Obviously there are potential markets such as aggregates which need to be sourced in future.

Anaerobic digester

A new composting facility has also been built to compost the fine organic material produced by the ball-mill recycling facility. All waste handling is within a fully enclosed building, with in-built air filters.The composting process occurs within 5 sealed, cylindrical digestion tanks.The organic waste is liquefied, heated and broken down by bacteria.Methane gas produced by the digestion process is converted to electricity (approximately 1.5 Megawatts - enough to power up to 1500 homes).The compost product
is marketed for agricultural use.