Tin is a silvery-white,
lustrous gray metallic element. Tin is soft,
pliable and has a highly crystalline structure. When a tin
bar is bent or broken, a crackling sound called a
“tin cry” is produced due to the breaking of the
tin crystals. People have been using tin for at least 5,500
years. Tin has been found in the tombs of
ancient Egyptians, and tin and lead were considered different
forms of the same metal. Tin was exported to Europe in large
quantities from Cornwall, England, during the Roman period,
approximately 2100 to 1500 BC. Cornwall was one of the world’s
leading sources of tin for much of its known history and into
the late 19th century.
The principal ore of tin is the mineral cassiterite,
which is found in Malaya, Bolivia, Indonesia, Thailand, and
Nigeria. About 80% of the world’s tin deposits occur
as unconsolidated placer deposits in river beds and valleys
or on the sea floor, with only about 20% occurring as primary
hard-rock lodes. Tin deposits are generally small and almost
always found closely allied to the granite from which it originates.
Tin is also recovered as a by-product of mining tungsten,
tantalum, and lead. After extraction, tin ore is ground and
washed to remove impurities, roasted to oxidize the sulfides
of iron and copper, washed a second time, and is then reduced
by carbon in a reverberatory furnace. Electrolysis may also
be used to purify tin.
Pure tin, rarely used by itself, was used as
currency in the form of tin blocks and was considered legal
tender for taxes in Phuket, Thailand, until 1932. Tin is used
in the manufacture of coatings for steel containers used to
preserve food and beverages. Tin is also
used in solder alloys, electroplating, ceramics, and in plastic.
The world's major tin research and development laboratory,
ITRI Ltd., is now over six years old as a private institution.
The laboratory is funded by companies that produce and consume
tin. The focus of the research efforts have been on possible
new uses for tin that would take advantage of tin's relative
non-toxicity to replace other metals in various products.
Some of the replacements could be lead-free solders, antimony-free
flame-retardant chemicals, and lead-free shotgun pellets.
No tin is mined in the U.S. currently.
Tin futures and options trade on the London
Metal Exchange (LME). Tin has traded on the LME since 1877
and the standard tin contract began in 1912. The futures contract
calls for the delivery of 5 metric tons of tin ingots of at
least 99.85% purity. The contract trades in terms of US dollars
per metric ton.
Prices – The average price of tin (straights)
in 2003 rose to .31 per pound from the 20-year year low of
.83 per pound seen in 2002 (i.e., since 1973). The average
price of ex-dock tin in New York rose to .32 per pound from
the 21-year low of .99 per pound in 2001 (i.e., since 1972).
Tin prices in 2003 recovered along with the rest of the basic
metal complex.
Supply – World mine production of tin
in 2002 fell sharply by 19% to a 3-year low of 249,000 from
308,000 as the marketplace reacted to lower prices. The world’s
largest mine producers of tin are China with 32% of world
production in 2002, Peru (26%), and Indonesia (22%). Mine
production in Peru has risen sharply in the last few years
and recent production levels in the 65,000-70,000 metric ton
range are more than double the levels seen in 1997.
World smelter production of tin fell –5.8%
in 2002 to 278,000 metric tons from 295,000 in 2001. The world’s
largest producers of smelted tin are Malaysia with 16% of
world production, China (14%), Indonesia (12%), and Brazil
(10%). The US does not mine tin, and therefore supply consists
only of scrap and imports. US tin recovery in 2002 fell to
7,750 metric tons from 7,800 in 2001.
Demand – US consumption of tin (pig)
in 2003 was on track to fall to about 45,800 metric tons from
46,655 metric tons in 2002 and post a new 6-year low. The
breakdown of US consumption of tin by finished products in
2002 shows that the largest consuming industry of tin is solder
(with 35% of consumption), followed by chemicals (21%), tin
plate (20%), and bronze and brass (8%).
Trade – The US relied on imports for
79% of its consumption in 2002. US imports of unwrought tin
metal rose to 42,200 metric tons in 2002 from 37,500 in 2001.
The largest sources of US imports in 2002 were China (with
7,600 metric tons of imports), Bolivia (6,150 metric tons),
Brazil (4,840 metric tons), and Indonesia (3,340 metric tons).
US exports of tin fell to 2,940 metric tons in 2002 from 4,350
metric tons in 2001. |
