Metals are often downcycled. For example, the high-quality steel used in automobiles—high-carbon, high-tensile steel—is “recycled” by melting it down with other car parts, including copper from the cables in the car, and the paint and plastic coatings. These materials lower the recycled steel’s quality. More high-quality steel may be added to make the hybrid strong enough for its next use, but it will not have the material properties to make new cars again. Meanwhile the rare metals, such as copper, manganese, and chromium, and the paints, plastics, and other components that had value for
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