Aluminum cans.Overview In 1964, Reynolds introduced one-way aluminum cans as a convenient alternative to returnable glass bottles and to steel cans, which still required a can opener. Until the 1980s, aluminum cans were used only for beer and soda, but now juice, energy drinks, and iced tea are also commonly packaged in cans. People like cans because they're light and unbreakable, and chill drinks quickly. Global consumption is estimated at 190-210 billion cans a year. That's 3 million tons of metal--about 10 percent of the world's aluminum supply--for a product with a useful life measured in minutes. [ILLUSTRATION OMITTED] Americans consume about 100 billion cans a year, or 340 per person, 10 times more than the average European and twice as much as the average Canadian, Japanese, or Australian. Consumption in emerging economies (including China, India, and the Former Soviet Union) hovers around 10 cans per person per year. As they develop, consumption will certainly rise. Closing the Loop Perhaps you've heard that cans are 100-percent recyclable, that recycling saves more than 90 percent of the energy used to make aluminum from ore, or that recycled cans are back on supermarket shelves in 60 days. [ILLUSTRATION OMITTED] That's all true. But recyclable doesn't always mean recycled. In 2004, only 45 percent of U.S. cans were recycled--better than U.S. rates for glass and plastic bottles (20-25 percent), but worse than can recycling elsewhere. Poverty and high scrap values scrap value See residual value. have produced a 96-percent recycling rate in Brazil, while Japan has an 82-percent rate thanks to national values of cleanliness and civic participation. Refundable deposits produce can recycling rates of 75-95 percent in Germany, Denmark, Sweden, Norway, 11 U.S. states, and seven Canadian provinces. [ILLUSTRATION OMITTED] In 2004, 810,000 tons of cans were landfilled in the United States United States, officially United States of America, republic (2005 est. pop. 295,734,000), 3,539,227 sq mi (9,166,598 sq km), North America. The United States is the world's third largest country in population and the fourth largest country in area. and about 300,000 tons in the rest of the world. That's like five smelters pouring their entire annual output--a million tons of metal--straight into a hole in the ground. Had those cans been recycled, 16 billion kilowatthours could have been saved--enough electricity for more than two million European homes for a year. Recycling just one soda can saves enough electricity to run a laptop computer for over 10 hours. Manufacturing Aluminum Each ton of primary aluminum requires about five tons of bauxite bauxite (bôk`sīt, bŏk`–), mixture of hydrated aluminum oxides usually containing oxides of iron and silicon in varying quantities. ore to be strip-mined (two-thirds of the total in Australia, Brazil, Guinea, and Jamaica), then refined into alumina alumina (əl `mĭnə) or aluminum oxide, Al2O3, chemical compound with m.p. about 2,000°C; and sp. gr. about 4.0. , producing several tons
of caustic red mud waste. The alumina is dissolved in cryolite cryolite or kryolite (both: krī`əlīt') [Gr.,=frost stone], mineral usually pure white or colorless but sometimes tinted in shades of pink, brown, or even black and having a luster like that of wax. and
zapped with an electric current to produce molten aluminum. This is
poured into ingots, then rolled into thin sheets used to make cans.
Primary aluminum production uses 2 percent of the electricity generated worldwide. One of the most overlooked impacts of aluminum production is habitat loss, not only from strip mining but from large hydroelectric dams built to supply primary smelters. These reservoirs have flooded thousands of square kilometers. As global demand rises, more dam and smelter projects are on the drawing boards in wilderness areas as disparate as Malaysia and Brazil. [ILLUSTRATION OMITTED] About a third of global primary smelting smelting, in metallurgy, any process of melting or fusion, especially to extract a metal from its ore. Smelting processes vary in detail depending on the nature of the ore and the metal involved, but they are typified in the use of the blast furnace. uses coal-generated electricity. Air pollution from primary smelting includes hundreds of thousands of tons of carbon monoxide carbon monoxide, chemical compound, CO, a colorless, odorless, tasteless, extremely poisonous gas that is less dense than air under ordinary conditions. It is very slightly soluble in water and burns in air with a characteristic blue flame, producing carbon dioxide; and carbon dioxide carbon dioxide, chemical compound, CO2, a colorless, odorless, tasteless gas that is about one and one-half times as dense as air under ordinary conditions of temperature and pressure. , as well as sulfur dioxide sulfur dioxide, chemical compound, SO2, a colorless gas with a pungent, suffocating odor. It is readily soluble in cold water, sparingly soluble in hot water, and soluble in alcohol, acetic acid, and sulfuric acid. and nitrogen oxide Noun 1. nitrogen oxide - any of several oxides of nitrogen formed by the action of nitric acid on oxidizable materials; present in car exhausts pollutant - waste matter that contaminates the water or air or soil , contributors to smog and acid rain. Per-fluorocarbons, potent greenhouse gases which linger in the atmosphere for thousands of years, are also released by primary smelting. --This Life Cycle Study was prepared by Jennifer Gitlitz, Research Director for the Container Recycling Institute in Washington, D.C. |
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