physical science curriculum supplement for grades 9 –...

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CyCles for sCienCe

Physical Science Curriculum Supplement For Grades 9 – 12

What’s A Mrf?LESS

ON

A Steel Cycles Program from the Steel Recycling Institute

The Steel Recycling Institute gratefully acknowledges the contribution of the educators and technicians who assisted in the development and field testing of these materials.

Editors/WritersDiana Rogers DLR Associates

William Weightman Belle Vernon Area School District

Associate Editors/WritersJim Woods Steel Recycling Institute

Carol Damian Dublin High School

Educational ReviewersBetty AltfaterSarah BinderJonathan ChorpenningVonnie ChristiansenLois E. DeLaney-CooperJohn B. GrenaMonroe E. HarbageRobert HateleyBarbara HilligossKathleen JonesPhilip LampeChris McCabeDeborah L. MillsSusan E. Rouch

Karen A. RussellJodi SchwartzFranklin TuttleGardner M. WatkinsSue WheelerMark D. Wylie

Technical ReviewerCharles G. Carson, III, Ph.D. U.S. Steel Group, USX Corporation

Contributors: Curriculum Development WorkshopDiane Cantrell, Ph.D. Ohio Department of Natural Resources

Lois E. DeLaney-Cooper Marion-Franklin High School

Kay Harmless Tipton School District

Jan Lingenfelter Washington State Department of Ecology

Steve Lippitt Groveport Madison High School

Robin Riordan The Ohio State University

Additional curriculum supplements and lessons available. To preview lessons: http://www.recycle-steel.org

@ 2009, 1996, 1995, 1994, 1993 Steel Recycling Institute. All rights reserved. Permission granted to educators to reproduce the curriculum supplement for classroom use.

EARTH SCIEnCE Melting Alloys Metals for ToastersMines to MillsProspecting for OreSink and Float Where in the World?

LIFE/EnVIROnMEnTAL SCIEnCEClimate Change and Waste Composting with Worms Food Spoilage and Waste Green Energy Leachate Collection Mining Our Landfills

PHySICAL SCIEnCEFluff StuffJumping Metals nails in Solution Steel HomesStretch and StrainWhat’s a MRF?

ACKNOWLEDGEMENTS

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For Additional Copies:

Cycles for Science curriculum supplements for Earth Science, Life/Environmental Science and Physical Science are available from the:

sTeel reCyClinG insTiTUTe680 Andersen Drive Pittsburgh, PA 15220-2700412/922-2772http://www.recycle-steel.org

raw Material/energy saved recyclables Game

raw Materials saved energy saved

$100 iron ore, limestone, coal$100 50 percent of the energy saved Hint: recycle 312 bottles to make a coat

$200 sand, soda ash, limestone$200 95% of the energy Hint: recycle 26 beverage cans to run your television for 3 hours

$300 oil, natural gas$300 75% of the energy Hint: recycle 1 lb. of cans to light a 60-watt light bulb for 1 day

$400 wood pulp, trees, water$400 68% of the energy Hint: recycle 1 ton of jars to save about 9 gallons of fuel oil.

$500 bauxite ore, coal$500 20% of the energy Hint: recycle 1 ton of print to power a home for 6 months

raw Material Answers: $100 steel, $200 glass, $300 plastic, $400 paper, $500 aluminum

energy saved Answers: $100 plastic, $200 aluminum, $300 steel, $400 glass, $500 paper

TEACHER LESSON PLAN: WHAT’S A MRF?

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A. PREPARATion

Collect materials and equipment for the demonstration, and for the group investigation. Provide students with copies of Student

Handouts A, B, C, D and E. Provide each group with the materials needed. Refer to Student Handout C for a complete listing of materials. For

the demonstration, you will need to laminate a poster-size copy of the Raw Materials/ Energy Saved Recyclables Game (see below.) For this

Jeopardy-like game, place a laminated card over each answer and on the front of the card indicate the dollar amount. The last row provides

the correct questions for each dollar amount. Cut off this row and glue it to the back of the game board. Make two sets of posters with the

questions: What is Paper? What is Steel? What is Plastic? What is Aluminum?

recommended instructional strategies

Concepts One part of the solution is recycling commonly used products and packages. The first step usually involves collecting household commingled recyclables. The commingled recyclables are most often sorted at a material recovery facility (MRF) and then transported to manufacturers who use them to make new products.

Essential Question: What is the most efficient process for collecting, sorting and processing commingled recyclables?

Objective Students will construct a Mini-MRF for collecting and sorting commingled recyclables.

National Science Science as Inquiry, Physical Science, Science in Personal and Social Perspectives. Education Standards

State Standards Link To locate the state academic content standards for this lesson, go to http://www.recycle-steel.org/ and click on Education and then Cycles for Science

Thematic Concepts Landfills, Recycling, Waste Managements, Steel Recycling

Other Subjects Social Studies, Mathematics, Language Arts

B. DEMonSTRATion

step 1: Brainstorm essential Question: What is the most efficient process for collecting, sorting and processing commingled recyclables?

Ask students to list the types of commingled recyclables that are often collected from households in your community. For each recyclable

material, identify its properties (e.g., density, magnetism) and a process to mechanically sort the material. Refer to Student Handout B: Flow

of Materials Through a MRF. Ask students what natural resources and energy are saved through recycling in preparation for Step 2.

Energy savings are industry estimated only; actual savings will vary depending on numerous circumstances.


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C. STUDEnT – GRoUP LAB invESTiGATion PRoCEDURES Guide students through scientific investigations

using the processes of scientific inquiry to complete the Student Inquiry Lesson: What’s a MRF?, Pages 7 and 8. For more information, refer to

national Science Education Standards “Scientific Inquiry” Pages 175 and 176. http://www.nap.edu/openbook.php?record_id=4962&page=175.

1. Problem/Question. Example: What type of machine/process is most efficient for collecting a recyclable item from among commingled

recyclables?

2. research showed. Refer students to Student Handouts A and B to prepare their statement.

3. Hypothesis/Prediction. Use the “i think that…” and “if…, then...” statements. Ask the students based on what they have researched and

observed, how they would write a hypothesis for the problem/question statement. Example: I think that the design of the “machine” or process

for separating commingled recyclable materials does/does not affect the amount and quality of the sorted material. If the machine/process is

effective in separating the commingled materials, then the materials sorted will be used and reduce dependency on raw materials.

4. How will you test your hypothesis? Ask students to explain how they would design their machine/process to test their hypothesis. Example: Build

a machine/process for sorting commingled materials and calculate the energy and raw materials saved.

5. Conduct investigation/record Data. Facilitate each step of the preparation and procedures for the group investigation as described on

Student Handout C: Group Investigation Procedures, Page 7.

6. Analyze/Graph Data. Create a graph showing the percentage of recyclables collected and contamination from Trials 1 and 2, and create a

classroom graph.

7. Draw Conclusions. Allow reasonable conclusions by students based on their own level of knowledge and actual observations. Discussion

about their conclusions should follow. The following are the questions and suggested responses to Student Handout D, Page 8. Question:

Which principles of physics apply in the operation of a MRF? Cite examples. Response: Students may refer to Example of Flow of Materials

Through a MRF or to their own mini-MRFs. Physics principles include work and motion (conveyor carrying materials down the line), magnetism

(sorting ferrous metals), gravity (materials falling off the conveyor), density (flotation and sorting of light fraction) and electricity (powering air

classifiers and conveyors). Question: your mini-MRF sorted a small volume of commingled materials. A large scale MRF may sort tons of

mate rials per hour. What problems do you think a large scale MRF might have with sorting? (Consider such factors as materials compaction

and labor.) How might these problems be solved? Response: A large scale MRF dealing with tons of materials may have a problem with

compression. Compressed materials do not sort as easily as loose materials. To overcome this problem, some MRFs utilize the “waterfall”

effect. Materials are moved on a series of conveyors positioned in such a way that materials cascade over the edge of one belt onto another

one underneath. The tumbling motion loosens materials for easier sorting. Operation of a commercial MRF can be labor intensive, which can

contribute significantly to costs. Some MRFs have mechanized portions of the sorting process, but still require manual sorting of mate rials for

which automated sorting is not available. For instance, plastics as a whole may be removed from the commingled mix mechanically, but

different types of plastic must be separated from each other by hand.

8. further investigations. Ask students to pose questions and possible redesign of the investigation to help test their hypothesis

and clarify their conclusions.

D. LESSon EnRiChMEnTS. Challenge students to complete one or more enrichment activity on Student Handout E:

Research and Real-World Applications, Page 9, and/or have them fine-tune their questions and comments from C.7 and C.8, then

design an investigation to further test their hypothesis to help find answers and draw conclusions.

step 2: raw Materials/energy saved recyclables Game. Choose two teams and provide each team with a set of questions: What is Paper?

What is Steel? What is Plastic? What is Aluminum? Explain that the first team to stand-up with the correct question wins the dollar amount on

the index card. Choose a team to begin the game. The first team will select Raw Materials Saved or Energy Saved category and a dollar amount.

As you remove the index card from the board, read the answer. The first team to stand up holding the poster with the correct question wins the

amount on the index card. Repeat allowing the second team to select a category and dollar amount until all answers are revealed. The winning

team will have the largest dollar amount.


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Student Handout A: Background and vocabulary

The sustainability of the planet and global warming are critical issues that require more attention to reducing worldwide

consumption of natural resources, saving energy and reducing reliance on landfills. One part of the solution is recycling commonly

used products and packages. Throughout the United States, many communities offer recycling programs. Residents may either

place recyclable materials at the curb, take them to a local drop-off site, or receive payment at a buy-back center. What many

people do not know is that collection is just one facet of the recycling process. Recyclables are sorted and processed at a

recycling facility and then transported to manufacturers who use the materials to make new products. The recycling loop is not

complete until new products are made from the recyclable materials. Consumers must purchase the recycled products to increase

the demand and markets for the recyclable materials collected. Otherwise, sorted recyclables must still be disposed of (usually) in

landfills.

The manufacturers who purchase the sorted material are looking for high quality material. It is the responsibility of the recycling

facility to clean, sort and bale the materials to meet the specifications of the manufacturer. Recycling facilities use a variety of

manual and mechanical means for preparing recyclable materials for shipment to the manufacturer, but the initial sorting and

cleaning begins with the resident. The following is a brief description of the process of preparing, collecting and transporting

recyclables from the home to the manufacturer. Many homeowners are asked to collect commingled recyclables, such as empty

steel food, aerosol and paint cans; glass jars; aluminum beverage cans; plastic jugs; soft-drink bottles; and newspapers. These

materials are usually commingled in a bin and placed at the curb for pickup. The recyclables are hauled to a recycling processing

facility for further sorting and processing. Many communities transport recyclables to a materials recovery facility (MRF, commonly

referred to as a murf).

At the MRF, materials may be separated into containers or placed on a conveyor for either manual or mechanical processing at

various sorting stations. newspaper and other grades of paper are often sorted manually. Commingled glass, aluminum cans,

steel cans and plastic bottles may be sorted using a combination of manual and mechanical techniques. As the commingled

mixture moves along the line, the ferrous metal (steel) is pulled out with magnets and loaded into a container to be baled,

shredded, or otherwise processed for shipping. The plastic (called the “light fraction”) may be initially pulled out by vacuum or

blower, or sorted by hand, followed by an additional sort to separate the plastic into type, such as HDPE (gallon jugs) and PETE

(soft-drink bottles). Once sorted, the plastic is mechanically compacted and baled. Glass is separated manually by color. Aluminum

continues to move down the line and eventually falls off the end into a container to be densified (made denser by compaction). All

along the sorting stream, workers must be attentive to ensure the materials are sorted correctly. For instance, if a glass jar is

placed in with steel, aluminum, or plastic, it must be manually removed. Each of these materials must be separated in order to sell

the material to a manufacturer. Much of the sorting process is labor intensive, but machines are used whenever possible to make

the job easier and to increase output. Keep in mind that this is just one example of how commingled recyclables might be

processed. Different facilities may utilize a number of different ways to process these materials. Once the recyclables are sorted

and baled, the bales are loaded onto trucks and shipped to manufacturers who will perform the final step in the recycling process-

manufacturing new products from the recycled materials. Purchasing recycled products is critical for providing momentum to

the cycle.

commingle (co-ming-gal) v. To become blended; mix together different elements.

commingled recyclables Mixed recyclables that are collected together after having been separated from mixed municipal solid waste (MSW). Commingled recyclables can include some or all of the following: brown, green, and clear glass; aluminum; steel cans; various plastics; office paper, newspaper, magazines; yard waste.

materials recovery facility (Mrf) A facility used for processing commingled recyclables


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Student Handout B: Flow of Materials through a MRF

Source: Eriez Magnetics, Erie, PA.

equipment list

1 Belt Magnet

2 Magnetic Pulley

3 Vibrator Feeder

4 Permanent Magnetic Eddy Current Separator


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Student Handout C: Group investigation Procedures

Concepts The sustainability of the planet and global warming are critical issues that require more attention to reducing worldwide consumption of natural resources, reducing landfill waste and saving energy. One part of the solution is recycling commonly used products and packages. The first step usually involves collecting household commingled recyclables1. The commingled recyclables are most often sorted at a material recovery facility (MRF) and then transported to manufacturers who use them to make new products.

Estimated One class period of 45 minutes. Time

Essential What is the most efficient process for collecting, sorting and processing commingled recyclables? Question

Materials/ All groups will need a container. Control groups will also need a ruler. All Mini-MRF groups will need access to assorted Equipment household items or lab equipment. The teacher will need a gallon plastic bag for the commingled recyclables. your teacher will assign your group the responsibility of preparing the materials/equipment and conducting the group investigation for one of following tasks:

Conveyor Belt: newspaper, tape and scissors to build a •conveyor belt, and a table

Control Aluminum: aluminum foil•

Control Paper: paper•

Control Plastic: foam plates•

Control Steel:100 paperclips (linked)•

Mini-MRF Aluminum: 100, pea size balls•

Mini-MRF Paper: 100, 1” paper squares•

Mini-MRF Plastic: 100, 1” foam plate pieces •

Mini-MRF Steel: 100 paperclips (not linked)•

PRoCEDURES

During this investigation, alll groups will work together to conduct a classroom simulation to sort commingled recyclables on a Mini-MRF:

1. Design mechanical sorting machine/process. Each Mini-MRF group must find household or lab equipment to use to sort their assigned

material from a commingled mixture of aluminum, paper, plastic and steel items (see Materials/Equipment). Draw a diagram of your

machine/process on a separate paper and include it with the data on Page 8.

2. set-up for the Mini-Mrf simulation. a) Place the 100 aluminum, paper, plastic and steel items in a gallon plastic bag; b) Ask the Conveyor

Belt group to position students below and at both ends of the table; c) Ask two students from each Mini-MRF group to find a place along the

conveyor belt to collect their assign material; d) Ask two students from each Control group to find a desk to “mine” their assigned raw

material.

3. Conduct Trials 1 and 2. a) Ask the Conveyor Belt group to start the conveyor belt and keep it moving; b) The teacher will drop the commingled

mixture onto one end of the conveyor belt; c) As the Mini-MRF groups sort their assigned material from the conveyor belt, the Control groups

must make 100 “raw material” items like those used by the Mini-MRF groups; d) As soon as the last piece of recyclable material reaches

the end of the conveyor belt, stop the Control and Mini-MRF groups; e) Count and record in the Table, Page 8, the number of Control items

produced and the Mini-MRF items sorted. Also calculate the percent of the Mini-MRF items sorted that are considered contamination (e.g., if

sorting for paper, plastic is a contaminate).

CoLLECTinG AnD AnALyzinG DATA Compare the percentage of Control items produced to the percentage of

the same material sorted on the Mini-MRF during Trial 1 and 2. Compare the time needed for the raw materials group to produce

and the Mini-MFR group to sort 100 items for their assigned materials.


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Student Handout D: individual Lab Report

1. Problem/Question: 2. research showed:

3. Hypothesis/Prediction: 4. How will you test your hypothesis?

Date name Class

Other Team Members

5. Collect and record data in the table below.

6. Analyze/Graph Data. Create a graph showing the percentage of recyclable materials and contamination collected during Trials 1 and 2. Attach work.

7. Draw Conclusions. Write a paragraph that summarizes the finding of your investigation. How would you design a machine/process for another type of recyclable material? Respond to the essential question, your question and hypothesis. Also respond to the following questions: Which principles of physics apply in the operation of a MRF? Cite examples. your mini-MRF sorted a small volume of | commingled materials. A large scale MRF may sort tons of mate rials per hour. What problems do you think a large scale MRF might have with sorting? (Consider such factors as materials compaction and labor.) How might these problems be solved? How would you design a machine/process for another type of recyclable material? Attach work.

8. further investigation: Pose questions and possible redesign of the investigation to help clarify your conclusions.

Trial/Team# newspaper

(% contamination)# steel

(% contamination)# Plastic

(% contamination)# Aluminum

(% contamination)

1 Control

Mini-Mrf

2 Control

Mini-Mrf


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Student Handout E: Research and Real-World Applications

Research

real-World Applications. Interview an administrator of a landfill or recycling facility and/or visit a MRF or recycling facility. Ask questions about the type of recyclables that are collected and sorted. Request information on the markets for each recyclable material, the types of manufacturers that purchase the sorted materials and the recycled products produced. Prepare a report on your findings. Consider ways to increase recycling at home, school and in the community. For more information on how to get started, contact the Steel Recycling Institute http://www.recycle-steel.org

Explore websites or other references and prepare a research paper in response to the following question:

What are other methods used by MRFs to sort commingled recyclables? •

Suggested Websites

http://en.wikipedia.org/wiki/Materials_recovery_facility•

http://www.sjrecycles.org/residents/mrf.asp•

Interesting Facts About A Clean and Dirty MRF (http://en.wikipedia.org/wiki/Materials_recovery_facility)

A clean MRF accepts recyclable commingled materials that have already been separated at the source from municipal solid waste generated by either residential or commercial sources. There are a variety of clean MRFs. The most common are single stream where all recyclable material is mixed, or dual stream MRFs, where source-separated recyclables are delivered in a mixed container stream (typically glass, ferrous metal, aluminum and other non-ferrous metals, PET [no.1] and HDPE [no.2] plastics) and a mixed paper stream, (including OCC, OnP, OMG, Office packs, junk mail, etc). Material is sorted to specifications, then baled, shredded, crushed, or otherwise prepared for shipment to market.

A dirty MRF accepts a mixed solid waste stream and then proceeds to separate out designated recyclable materials through a combination of manual and mechanical sorting. The sorted recyclable materials may undergo further processing required to meet technical specifications established by end-markets while the balance of the mixed waste stream is sent to a disposal facility such as a landfill.

The percentage of residuals (unrecoverable recyclable or non-program materials) from a properly operated clean MRF supported by an effective public outreach and education program should not exceed 10 percent weight of the total delivered stream and in many cases it can be significantly below 5 percent. A dirty MRF recovers between 5 percent and 45 percent of the incoming material as recyclables, then the remainder is landfilled or otherwise disposed. A dirty MRF can be capable of higher recovery rates than a clean MRF, since it ensures that 100 percent of the waste stream is subjected to the sorting process, and can target a greater number of materials for recovery than can usually be accommodated by sorting at the source. However, the dirty MRF process is necessarily labor-intensive, and a facility that accepts mixed solid waste is usually more challenging and more expensive to site.

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RESOURCES

Aluminum Association 900 19th St., NW, Suite 300 Washington, DC 20006 202/862-5100 http://www.aluminum.org

American Forest and Paper Association 1111 19th St., NW, Suite 800 Washington, DC 20036 202/463-2420 http://www.afandpa.org/

American iron and Steel institute 1140 Connecticut Ave., NW, Suite 705 Washington, D.C. 20036 202/452-7100 http://www.steel.org

American Plastics Council 1300 Wilson Blvd. Arlington, VA 22209 703-741-5000 http://www.americanchemistry.com/plastics/

Aseptic Packaging Council 2111 Wilson Blvd., Suite 700 Arlington, VA 22201 703/351-5062 http://www.aseptic.org

Can Manufacturers institute 1730 Rhode Island Avenue, NW Suite 1000 Washington, DC 20036 202/232-4677 http://www.cancentral.org

Glass Packaging institute 700 North Fairfax Street, Suite 510 Alexandria, VA 22314 703/684-6359 http://www.gpi.org

institute of Scrap Recycling industries 1325 G Street, NW, Suite 1000 Washington, DC 20005 Tel 202/737-1770 http://www.isri.org

Keep America Beautiful 1010 Washington Boulevard Stamford, CT 06901 203/323-8987 http://www.kab.org

national Recycling Coalition 805 15th Street, NW, Suite 425 Washington, DC 20005 202/789-1430 http://www.nrc-recycle.org

national Wildlife Federation 11100 Wildlife Center Dr. Reston VA 20190 800/822-9919 http://www.nwf.org

Steel Recycling institute 680 Andersen Drive Pittsburgh, PA 15220-2700 412/922-2772 http://www.recycle-steel.org

U.S. Geological Survey 12201 Sunrise Valley Drive Reston, VA 22092 703/648-4972 http://www.usgs.gov

physical science curriculum supplement for grades 9 –...

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