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What's
A MRF--Procedure
1. Copy onto a transparency or use as a handout Example of Flow of Materials
Through a MRF (GIF Link Below). As you show the figure, explain that a
MRF is a facility for processing commingled (mixed together) recyclables.
Describe the flow of materials through the various sorting stations. Identify
the properties of each type of recyclable material (e.g., mass, magnetism)
that impact the design of each sorting station.
2.
As a class, decide on dimensions of the mini-MRF.
- Divide
the class into lab groups.
- Assign
each group one station of the mini-MRF to design and operate:
- Conveyor
to move materials Blower to sort out the light fraction (paper,
plastic)
- Magnet
system to sort out ferrous metals (paper clips, safety pins)
- Flotation
system to sort nonferrous metals from each other
- The following
are suggestions for creating a simple, manually operated MRF:
- Conveyor
- Tape together sections of newspaper to make the conveyor belt.
- Drape
the belt around a table.
- Blower
- Make fans of construction paper.
- Magnet
system - Attach bar magnets to the bottom of a non-coated, steel
cookie sheet.
- Flotation
- Position a plastic tub of water at the end of the conveyor. Use
a kitchen strainer to scoop off materials that float.
3.Prepare
the recyclable materials.
- Commingle
a quantity of each of the recyclable materials listed in "Materials/Equipment."
- Provide
each group with a small amount of the commingled recyclables with which
to test their designs as they develop them.
4.For
further study:
- Quantify
effectiveness of the sorting process. Mass each recyclable material
prior to commingling. After each trial run, assist groups in calculating
the percentage of material collected at their stations and others using
the formula:
- mass
of each item sorted properly x 100, then divide it by the total mass
of that item Mechanize the MRF.
- Encourage
students to think of methods for reducing the manual labor involved
in sorting materials. Refer to Scheme of a Mechanical Mini-MRF for ideas.
- Create
a video presentation to share with other student groups. Produce an
interesting and scientifically accurate story about a MRF and the sorting
process.
- Use the
development of the classroom MRF, including processes that did not work
and how problems were overcome, to reinforce physics concepts while
promoting awareness about the challenges and solutions of recycling.
- Continue
to page 3: Activity Analysis
CYCLES
FOR SCIENCE RESOURCES
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