Given that its uses now transcend as mere bling in the
jeweler’s world, does platinum today truly qualify as the world’s most
versatile precious metal?
By: Ringo Bones
Lately, platinum gained the mainstream media’s attention
when in August 16, 2012, when 34 striking mine workers over a wage dispute in a
Lonmin owned platinum mine located in the town of Marikana, South Africa got
shot and killed by the local police force. The news of the class sent the global
price of platinum rising to 30 US dollars per troy ounce during that day’s
trading. Given that South Africa supplies 75% of the world’s platinum needs,
the striking workers’ demands for pay raise can only be described as fair. And
for some time now, gold has been more expensive than platinum – as by August
17, 2012 platinum prices hovered in the 1,450 US dollars per troy ounce mark as
opposed to gold’s 1,600 US dollars per troy ounce level. Given that platinum
may soon again be more expensive than gold, will platinum’s price premium truly
justified by its title as the world’s most versatile precious metal?
Platinum, named after
platina or little silver is the most abundant and most used member of the
platinum metal family, which includes iridium, osmium, palladium, rhodium and
ruthenium. Placed in the second transition metals region of the Periodic Table
of elements, ancient artifacts made of metallic platinum have been unearthed.
Though platinum wasn’t known as a distinct metal until 1557 when it was
discovered in Mexico by the Italian poet and adventurer named Julius Caesar
Scaliger. In 1741, the first sample of the metal was bought to Europe by an
English metallurgist named Charles Wood.
The world’s leading producer of platinum is the Republic of
South Africa while other major producers are Canada, Russia and former Soviet
states in Central Asia. Platinum occurs in both native – as in elemental state
and in compounds. In its native state, It is usually occurs in sandlike grains
in placer deposits with similar grains of the other metals of its family or
with copper, cobalt, nickel or gold ores. However, large nuggets of platinum
have also been found. The most important of the platinum ores are sperrylite –
platinum arsenide, and cooperlite – platinum sulfide.
Platinum is the last element in Group VIIIA of the Periodic
Table. It is a silvery metal, soft, dense very ductile and malleable, and with
a high tensile strength. Its electrical conductivity is comparatively low, and
its coefficient of expansion is the lowest of the commercially produced metals.
Platinum is untarnished by air, but vaporizes appreciably at red heat. The
halogens, including fluorine, have no effect at ordinary room temperature and
single mineral acids do not dissolve platinum. Aqua Regia (a mixture of nitric
and hydrochloric acid) and a mixture of hydrochloric and chloric acids dissolve
the metal. It is also attacked at high temperatures by fused nitrates, acid
sulfates, hydroxides, peroxides, sulfides, iodine, phosphorous, arsenic,
carbon, silicon, selenium and tellurium.
At present, most of the platinum commercially produced not
destined for jewelry use go into the making of catalytic converters in modern
automobiles where they remove most of the nitric and sulfuric oxides found in
car exhausts. Because of its relative chemical inactivity, platinum, both as a
free metal and alloyed with rhodium, is an almost indispensable material for
such devices as magneto contacts, spark-plug electrodes, radar parts and in critical
analog computer components of World War II era bombsights. In the chemical – as
in petrochemical – industries, platinum and its alloys are essential catalysts
– for example in making nitric acid from ammonia; As spinnerets and bushings in
the production of rayon and glass fiber; As electrodes in industrial processes
involving anodic oxidation – as in producing perchlorates and peroxides and
electrodeposition of nickel and rhodium and for corrosion and heat-resistant
treatment of measuring and recording devices. In addition, platinum has been
used extensively in jewelry, dentistry, X-Ray equipment, laboratory apparatus,
medical and surgical instruments and heating units (bomb calorimeters).