by kevin, on January 29th, 2010
For our fourth class, I turned over lecture duties to the students. As I mentioned in an earlier post, the students will do three profile projects – one about materials and/or resources, one about companies and/or people, and one about certifications and/or labels. Last week they selected a material and/or resource to research and investigate. This week, they presented their findings. Too often we have no knowledge of the materials that make up the manufactured objects that surround us every day. To start imagining how those products can be manufactured utilizing cradle to cradle thinking, we first have to know what materials are being used, where they come from, how they’re produced, how much energy or water is used in their production, whether they are scarce or abundant, whether they’re difficult or easy to extract, whether they can be recycled or reused, and much more.
Before I began looking seriously at materials, I only had a vague notion where they originated – carpet comes from Georgia, wood comes from the pacific northwest, brick comes from the southeast, cork comes from Portugal, and so on. I would blindly specify an aluminum window system without any thought for how that product was produced. Only later did I really know the story of aluminum’s journey that starts as mined bauxite deep within the Australian continent. Although aluminum is incredibly plentiful – some estimates put it at the third most abundant element in the Earth’s crust, and most abundant metal – it’s not naturally available in it’s pure elemental form. Chemical treatments known as the Bayer process separate alumina, or aluminum oxide, from the mined bauxite. Alumina is typically shipped to China, South Africa, Ghana, or New Zealand where pure aluminum is separated from the oxygen through the Hall-Héroult process. The alumina is dissolved in molten cryolite and electrified to reach its high melting point of 3632∘F. Although this process consumes a tremendous amount of energy, it’s the most inexpensive and viable method to create a reliable supply of pure aluminum. It’s vacuumed out of smelting pots and poured into slabs that are shipped around the world. Recycled aluminum requires a fraction of the energy to produce compared to virgin material.
Without even thinking about it, I was routinely selecting and using materials for which I had only limited knowledge. We take the aluminum in our cars, or computers, or soda cans for granted without really considering the complex undertaking required to bring those products to market. Knowledge is liberating and empowering and aids significantly in making informed decisions. These kinds of questions are what I asked the students to explore.
Several weeks ago I supplied them with a list of potential materials and/or resources that could be interesting. Or, at least they were interesting to me. But most made unexpected choices, so I was pretty excited to see what they would find and report. The materials/resources they selected were beef, bamboo, manganese, plastic laminate, adhesive, cork, paper, aluminum, bottled water, zinc, leather, cloth, activated carbon, hemp, and sugar. An interesting collection.
This week, class was conducted by the students as they taught me, and their fellow students. Each was required to present a ten minute overview of the material they had selected. Three students were absent and will give their presentations this coming week, so it’s too early for me to report on their reports. I’ll do that soon. I will say this, though, there were some fascinating discoveries that certainly surprised me, and I hope informed the students.
If you have any interesting material/resource stories please let us know, we’re always eager to learn more.