Page 236 - Materials Chemistry, Second Edition

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Municipal Solid Waste Processing; Materials Recovery Facilities 207
Collection vehicle
Source-separated
materials
Receiving area

Front-end loader
spreads waste
for presorting Cardboard
Source-separated
materials in see-through
First-stage manual bags
presorting Bulky items
white goods
Front-end loader, other contaminants
and inclined
conveyer system

Second-stage Cardboard
manual presorting Other large items Collection
vehicle
Inclined conveyor

Bag breaker
Bagged
Paper commingled
Cardboard
Conveyor recyclable
Plastics materials
Glass
First-stage Aluminum cans
manual sorting
Steel cans
Conveyor Paper
Conveyor Plastics
Screening Second-stage Glass
(trommel or disc) Oversize material manual sorting Aluminum
cans
Steel cans
Conveyor
Conveyor
Truck
Magnetic Ferrous
separation metals
Conveyor
Shredding

Landfill RDF Compost for daily
landfill cover
FIGURE 7.39 MRF flow scheme for a dirty MRF. (From Vesilind, P.A. et al., Solid Waste Engineering, 1st
ed., Brooks/Cole, Pacific Grove, CA, 2002. Reproduced with kind permission of Brooks/Cole, a division of
Thomson Learning: www.thomsonrights.com.)

7.6 THE CONTAMINATION ISSUE
Depending on the design of the MRF, the quality of the separated product will vary significantly.
Mixed MSW received at the facility poses the greatest challenge to ensuring separation of clean,
quality product. For this reason it is advantageous to require some initial separation, ideally by the