Materials Removal Facility (MRF) - Up Front
Basically the MRF consists of a feed hopper and in-feed conveyor leading to an initial pick station where hand removal of large objectionable/problem items and clean corrugated material takes place. A conveyor and baler are positioned below the pick station to continuously bale the corrugated material. This baler is also used to bale accumulated aluminum and ferrous products during slow or off- peak times.
Small Materials (Fines)
A trommel follows acting as a bag opener, and for screening out the small and mid-size fractions of the waste stream. The small fraction, called fines, consists of food scraps, dirt, glass, and many other low BTU content materials under 3-inches in diameter.
The fines are disposed of in a lined MSW cell in the Polk County landfill and make excellent fill for cracks and voids created by large items such as furniture.
The mid-size materials, under 7-inches in diameter, are also screened out in the trommel. This waste stream is conveyed through magnetic separation to remove ferrous items, passes over an eddy current system which removes the aluminum, and is then combined with the over-size stream which exits the end of the trommel.
The over-size stream also passes through magnetic separation for ferrous removal. Magnetic and eddy current separation have proven to be much more efficient than manual removal and the added costs are financially justified. This also minimizes employee requirements, and risk of exposure to hazardous materials.
Final Pick Station
The combined mid-size and over-size waste streams pass through a final pick station before being conveyed to the tipping floor for processing in the waste combustors.
The final pick station platform is designed to capture materials that escape the initial pick and the mechanical separation process. It also has the capability to focus on the removal of other recyclables that are exposed after passing through the trommel.
This waste stream that is delivered to the tip floor consists largely of high BTU paper and plastic products.