2. Have students create a simple diagram of stages in the cycle of leaves (leaves fall to ground, leaves decay and enrich soil, enriched soil helps trees grow, trees produce leaves, leaves fall to ground, etc.)
| HANDOUT: | Aluminum Can Recycling |
| SUBJECT AREAS: | Science, Social Studies, Language Arts, Math, Citizenship |
| TEACHING OBJECTIVE: | To give students a better understanding of aluminum, a nonrenewable but recyclable resource they use every day. To review the concept of cycles with students. To give an overview of the life cycle of aluminum and aluminum cans. To introduce the concept of closed-loop recycling as it pertains to aluminum cans and set the stage for learning about lightweighting. |
| SKILLS: | Discussion, Observation, Cycle Recognition, Problem Solving, Inquiry, Sequencing, Persuasive Reasoning, Kinesthetic Concept Development, Research, Reporting |
| MATERIALS: | Part One:
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| KEY VOCABULARY: |
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| TEACHER TIP: | You can do this lesson in two parts, as indicated, or as one extended lesson. |
| TIME: | Preparation Part One: Collect dead leaves and soil, 10 minutes Draw examples of cycles on board or flipchart (steps 2-5), 10 minutes Prepare clay for model can making exercise, 10 minutes Class Time Part One: 30-35 minutes Part Two: 30-35 minutes |
Environmental education is grounded in an understanding of processes and systems that make up the environment. Environmental literacy rests on a deeper understanding of how natural and human systems interact to shape the environment. Cycles apply to both natural and human-made systems. In this lesson, students recall what they know about cycles and explore the life cycle of an aluminum can.
Review the background information on aluminum can manufacturing provided in the first section of this kit. A simplified version has been provided to hand out to students. Today aluminum is used extensively in cars, airplanes, boats and other vehicles because of its light weight, its strength and its resistance to corrosion. Because it doesn't react with foods, it is used for food and beverage packaging. It can be rolled, squeezed and cut into almost any shape. Its conduction properties make it an efficient metal for chilling beverages, and its nonmagnetic properties are useful in electronics. Aluminum can be recycled again and again without losing its strength.
Producing aluminum from bauxite takes a lot of energy and raw material. For every ton of alumina extracted from bauxite, there is an almost equal amount of leftover material. Researchers are looking for ways to use the leftover material but so far have not found any uses that are economical.
In comparison, recycling aluminum saves about 95 percent of the energy needed to make new aluminum from ore. In the recycling process, aluminum melts to form ingots or rods, which are later remelted and formed into new products. Recycled aluminum can also be melted directly into new products.
This lesson builds on what students already know about recycling and aluminum can manufacturing. The lesson emphasizes that recycling saves landfill space by creating an alternative to disposal and that recycling cans conserves natural resources and saves energy. Students learn that aluminum can recycling is an example of closed-loop recycling. The recycled aluminum beverage can returns to the grocer's shelf as a new, filled can in as few as 60 days after collection.
PROCEDURE
2. Have students create a simple diagram of stages in the cycle of leaves (leaves fall to ground, leaves decay and enrich soil, enriched soil helps trees grow, trees produce leaves, leaves fall to ground, etc.)
3. Note that this process is called a cycle. Cycles are important aspects of life; a cycle may go through many phases, but it always goes back to where it started. Explain to students that there are endless cycles around us. Ask students to suggest other cycles they know of (day-night; spring-summer-fall-winter).
4. Packages go through a life cycle, too. Ask students to suggest how a package might have a life cycle. (A resource is used to make a package, the package is used to transport a product, the product is used, and the package is thrown away or recycled.)
5. Ask students to think about the aluminum beverage can. What do they think the cycle for a can is? Illustrate their cycles on the board. (Option: have students work in groups to draw their cycles and then present them to the class.) Do they know where aluminum comes from? (Fill in with background information, as needed, using a world map to show countries where bauxite is mined.) Have them copy the cycle they think makes the most sense into their science notebooks.
6. Tell students they're going to explore how an aluminum can is made. Can they make a can using only two pieces of clay? Distribute clay to each student. Allow them 5-10 minutes to make a clay can. Discuss their designs. Afterwards, use the can manufacturing handout to explain the can manufacturing process.
Part Two: The Complete Life Cycle of Aluminum Cans (Closed-Loop Recycling)
7. Refer to the cycles students proposed in step 5 of the procedure. Ask them to consider the following "big picture" cycle for aluminum cans (this can be done ahead of time on the chalkboard or flipchart):
Ask students to recall what they learned in Lesson 1 about renewable and nonrenewable resources. What problems are there in this cycle? (bauxite will get used up eventually) What is the last stage in the cycle? (landfill resources thrown away) What hidden resources are also thrown away? (energy to make cans)
8. How can you change the can making cycle to prevent those problems? How can we make this a "true" cycle that comes back to the starting point? (Change "Use cans, then throw away" to "Return cans to can company or recycling center.") Some students may also suggest, based on the clay models, that they could use less material to make each can. Or they might suggest using a package that is reusable. If so, explain that this is called "lightweighting" and they'll learn more about lightweighting later.
Distribute the aluminum can recycling handout. Change the diagram on the flipchart to reflect recycling. (If appropriate for your class, build on the concept that "re-cycle" means to put the product back into the loop so that the cycle can continue unbroken.) Note that when products are recycled, they do not become part of the garbage but go back to become something new, just like the leaves go back into the soil to help a new tree grow.
9. When the old product becomes new again (as when old aluminum cans are recycled into new aluminum cans) this process is called closed-loop recycling. Ask them to revise their "aluminum can life cycles" in their science notebooks to reflect what they now know about the can manufacturing process.
WRAP UP
2. Write a story about "one day in the life of an aluminum can."
3. Imagine that a new family moves into your neighborhood. You notice that the family tosses its aluminum cans in with the rest of the garbage rather than recycling them. Write out the positions (viewpoints) a person might use for or against recycling aluminum cans. Develop the arguments into a script, then act it out. Have your classmates decide which argument was most convincing and why. (Option: do this activity in small groups and then present your skit, as a group, to the class.)
4. Create a poster about recycling aluminum cans. Remember to include a title for the poster. Display the poster near a soda machine in your school, neighborhood store, or community recreation center.
5. Select another item and show its life cycle in a drawing or diagram.
EXTENSIONS
2. With some classmates, act out the can manufacturing process in mini-dramas. "Gas" and "Oil" may want to help get some of the materials mined, shipped and transported. "Heat," "Electricity" and "Water" can join the group during the manufacturing process. Set up scenarios in which consumers demand more products and have resources move to one side of the room, making them less available to manufacture other materials. How does a shortage of resources affect what can be manufactured? How could we solve the problem of limited resources? (Some students may substitute recycled materials for limited resources; this would reduce energy and resource demands.)
3. One of the ways to conserve resources in the aluminum can manufacturing process is to "close the loop." Choose from the following activities (or save them for a culminating project, as described in Lesson 7):
a. Identify aluminum can recycling centers in your neighborhood. Check the Yellow Pages under recycling, aluminum, resource recovery or scrap metals. Or contact a local government agency such as your county and municipal waste authority or the department of public works. Create and post a list of where to take cans for recycling.
b. Decide if you want to create and implement a plan to ensure that cans get recycled at home, at school or in your neighborhood. Even if your area has a recycling program, many cans are probably not getting recycled. (According to the Can Manufacturers Institute, the aluminum industry currently recovers two out of three cans.) The Great Aluminum Can RoundUp (see resource kit information) offers some suggestions on how to get started and also sponsors various recycling competitions.
REFERENCES
2. Parts of this lesson are adapted from The Museum of Solid Waste and Energy, Copyright 1996, The NEED Project, and are reproduced with permission of The NEED Project, P.O. Box 2518, Reston, VA 20195.
3. Parts of this lesson were adapted from "Counting Our Resources," 4Rs Project: A Solid Waste Management Curriculum for Florida Schools, 1990, pages 5-12.
4. Parts of this lesson were adapted from "What's In a Cycle?" Peace Corps Outreach Materials on Waste and Recycling, 1995, pages 3-4.
5. Parts of this lesson were adapted from "Let's Reduce and Recycle: Curriculum for Solid Waste Awareness," Environmental Protection Agency, 1990, pages 40-41.
