YOU HAVE IT ALL WRONG!!!!!
Tin is one of the earliest metals known and used. Because of its hardening effect on copper, tin was used in bronze implements as early as 3,500 B.C., although the pure metal was not used until about 600 B.C. About 35 countries mine tin throughout the world. Nearly every continent has an important tin-mining country. Tin is a relatively scarce element with an abundance in the earth's crust of about 2 parts per million (ppm), compared with 94 ppm for zinc, 63 ppm for copper, and 12 ppm for lead. Most of the world's tin is produced from placer deposits; at least one-half comes from Southeast Asia. The only mineral of commercial importance as a source of tin is cassiterite (SnO[SUB]2[/SUB]), although small quantities of tin are recovered from complex sulfides such as stanite, cylindrite, frankeite, canfieldite, and teallite.
Most tin is used as a protective coating or as an alloy with other metals such as lead or zinc. Tin is used in coatings for steel containers, in solders for joining pipes or electrical/electronic circuits, in bearing alloys, in glass-making, and in a wide range of tin chemical applications. Secondary, or scrap, tin is an important source of the tin supply.
Aluminum is the second most abundant metallic element in the Earth's crust after silicon, yet it is a comparatively new industrial metal that has been produced in commercial quantities for just over 100 years. It weighs about one-third as much as steel or copper; is malleable, ductile, and easily machined and cast; and has excellent corrosion resistance and durability. Measured either in quantity or value, aluminum's use exceeds that of any other metal except iron, and it is important in virtually all segments of the world economy. Some of the many uses for aluminum are in transportation (automobiles, airplanes, trucks, railcars, marine vessels, etc.), packaging (cans, foil, etc.), construction (windows, doors, siding, etc), consumer durables (appliances, cooking utensils, etc.), electrical transmission lines, machinery, and many other applications.
Aluminum recovery from scrap (recycling) has become an important component of the aluminum industry. A common practice since the early 1900's, aluminum recycling is not new. It was, however, a low-profile activity until the late 1960's when recycling of aluminum beverage cans finally vaulted recycling into the public consciousness. Sources for recycled aluminum include automobiles, windows and doors, appliances, and other products. However, it is the recycling of aluminum cans that seems to have the highest profile.
Please not that only Tin is noted for being a protective coating.
FYI: I plagiarized all of this. Directly from
http://minerals.usgs.gov/minerals/