Material recovery facilities receive recyclables collected from curbside pickups. Trucks dump the loads which are then sorted through a process involving breaking open bags, conveying materials to sorting lines where staff separate items into bins by material type. The sorted materials are baled and stored for shipment. MRFs use various mechanical and manual techniques like size reduction, air classification, screening, and magnetic separation to efficiently separate and prepare recyclables for end users.
2. Where do they go?
• Many towns and
municipalities offer
recycling services that
pick up materials like
paper, plastic and
cardboard from the curb.
• Where do these materials
go after pickup?
3. Material Recovery Facility (MRF)
• Once recyclables are picked up from the curb on
trash day, they are generally transported to a
material recovery facility.
4. Recyclable Materials
• Recyclable materials include
plastic containers and bottles
and fiber materials such as
phonebooks and newspapers.
• Plastic bags are more difficult
to recycle and are not accepted
at most MRFs because they
create problems during
processing.
• The first step in recycling is
proper separation and sorting of
materials curbside, so the
individual who recycles has an
important responsibility
5. At the MRF
• At an MRF, trucks drop off load of
recyclables in the receiving area.
• The trash and non-recyclable items
are removed from the recycling
process and the clean recyclables are
sorted.
• Bags of materials are broken open,
and a conveyor transports the
recyclables to a sorting line.
• There, MRF staff manually sort out
the different types of materials into
various holding bins.
• The recyclables are then transported
via an incline conveyor into a baler,
which crushes the materials together
and binds them with wire bands.
• The bales are then stored in stacks
for shipment.
6. The Don’ts
• Materials that are not recyclable
must be separated from the waste
stream because they can create
problems in the recycling process.
• Some examples of non-recyclable
materials include aluminum foil,
Styrofoam, food wraps, ceramic
and clay pots, porcelain, light
bulbs and fabrics.
7. Defination:
A materials recovery facility is a specialized plant that
receives, separates and prepares recyclable materials
for marketing to end-user manufacturers.
There are three types of MRF:
Clean MRF
Dirty MRF
Wet MRF
8.
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11. Principle of Material Recovery Facility
• Mixed solid waste are separated based on their source for
recovery of materials.
• The process depends on degree of source separation of
waste.
• The nature and design of each unit process accommodate
the physical and chemical characteristics of the source
material.
• Resource recovery plays an important role in the
economies of developing nations
13. Process involved in MRF
Techniques
Manual methods Mechanical methods
• Electromagnetic
separation
• Fluid dynamics
• Pneumatics
• Others
Processes:
• Size reduction
• Air classification
• Screening
14. Manual Processing
• Bulky items (appliances, furniture, etc.) and specified
contaminants (e.g., hazardous waste)
• Manual separation is applicable to the removal of
contaminants from source-separated materials
• Equipment involved in manual separation of materials
usually includes a sorting belt or table, which contains a
mixture of materials
• Hoppers or other receptacles for receiving removed items are
positioned within easy reach of the sorters.
15. Manual Processing
• Newspaper (700 to 4,500kg/hr/person)
• Corrugated (700 to 4,500kg/hr/person)
• Glass containers (mixed colour) (400 to 800kg/hr/person)
• Glass containers (by colour) (200 to 400 kg/hr/person)
• Plastic containers (PET, HDPE) (140 to 280 kg/hr/person)
• Aluminum cans
17. Size reduction Technique
• The term “size reduction” has a number of synonyms
in solid waste management, including “shredding”
and “grinding”.
• Reduces bulky items to particles, the sizes of which
are compatible with the processing equipment.
• This uniformity is a requirement of some mechanical
sorting systems
18. Size reduction Technique
• The hammer mill is a type of high-speed shredder
frequently used for size reducing solid waste.
• Low-speed, high-torque; flail mill-type shredders;
and shear shredders are also used in some cases for
size reducing solid waste.
• On the basis of orientation of the rotor -- namely,
horizontal and vertical.
21. Shear shredders
Shear shredder is also used to size
reduce mixed waste. This size reduction
device is characterized by its high
torque and low rpm.
The unit consists of two horizontal,
counter rotating shafts. Each shaft
contains cutters to tear and shear the
material.
In shear shredders, shear and
deformation are the primary
mechanisms of particle size reduction.
The cutters typically operate within a
range of 20 to 70 rpm.
22. AIR classification
• Air classification is a process of separating categories of
materials by way of differences in their respective
aerodynamic characteristics.
• The aerodynamic characteristic of a particular material is
primarily a function of the size, geometry, and density of the
particles.
• The suspended fraction conventionally is referred to as the
“air classified light fraction” and the settled fraction is termed
“air-classified heavy fraction”.
• The confined volume in which the separation takes place is
called an “air classifier”.
24. Screening
• Screens are used for achieving efficient separation of
particles through dependence on differences between
particle sizes with respect to any two dimensions.
• Screening process: Oversized feedstock, Undersized
feedstock
25. Types of Screening
Trommel Screening:
• The trommel has proven to be quite effective and efficient for
processing mixed waste and other mixtures where large, flat
particles (e.g., paper) and aggregate-type particles (e.g.,
crushed glass) must be separated.
26. Types of Screening
Disc screen:
• Disc screens have been employed in many waste processing
facilities. The predominant applications to date are effecting
the separation of inorganic materials from refuse-derived fuel
fractions, from paper materials, or from wood waste.
27. Magnetic Separation
• Magnetic separation is a process used to segregate
magnetic (i.e., ferrous) metal from a mixture of
different types of materials, e.g., mixed waste or
commingled metal, glass, and plastic containers. The
process is technically simple and of relatively low
cost.
28.
29. Aluminium and Glass Separation
• The predominant non-ferrous metal represented in the
waste stream is usually aluminium, and it is oftentimes a
target for recovery.
• In the case of aluminium, heavy media and eddy current
separation are possibilities.
• Eddy current separation is, at present, the more
commercially feasible.
• Separation is brought about by the ejection of aluminium
particles from a moving waste stream due to the force
exerted on the metallic particles as they pass through an
electromagnetic flux generated by the equipment.
30. Conclusion
• By Material recovery facility the Waste
management system functions efficiently.
• MRF methods provides recycling of raw
materials for Industrial uses.
