Mercury

Mercury was known to the ancient Hindus and Chinese, and was also found in Egyptian tombs dating back to the 1500s BC. The ancient Greeks used Mercury in ointments, and the Romans used it in cosmetics. Alchemists thought mercury turned into gold when it hardened.

Mercury, also called quicksilver, is a heavy, silvery, toxic, transitional metal. Mercury is the only common metal that is liquid at room temperatures. When subjected to a pressure of 7,640 atmospheres (7.7 million millibars), mercury becomes a solid. Mercury dissolves in nitric or concentrated sulfuric acid, but is resistant to alkalis. It is a poor conductor of heat. Mercury has superconductivity when cooled to sufficiently low temperatures. It has a freezing point of about –39 degrees Celsius and a boiling point of about 357 degrees Celsius. The atomic symbol for mercury is Hg and its atomic number is 80.

Mercury is found in its pure form or combined in small amounts with silvers, but is found most often in the ore cinnabar, a mineral consisting of mercuric sulfide. By heating the cinnabar ore in air until the mercuric sulfide breaks down, pure mercury metal is produced. Mercury forms alloys called amalgams with all common metals except iron and platinum. Most mercury produced is used for the manufacture of industrial chemicals and for electrical and electronic applications. Other uses for mercury include its use in gold recovery from ores, barometers, diffusion pumps, laboratory instruments, mercury-vapor lamps, pesticides, batteries, and catalysts. A decline in mercury production and usage since the 1970s reflects a trend for using mercury substitutes due to its toxicity.

Prices – The average free market price of mercury in 2003 rose sharply by 19.5% from 2002 to a 6-year high of $184.07 per flask (34.5 kilograms). That was right on the 10-year average price.

Supply – World mine production of mercury in 2002 rose +20.8% to 1,800 metric tons from 1,490 metric tons in 2001. The world’s largest miners of mercury are Algeria with 44.4% of world production in 2002, followed by Spain (16.7%), and China and Kyrgyzstan (both with 13.9%). World mercury resources are estimated in excess of 500,000 tons, mostly in Kyrgyzstan and Spain, which if accurate, suggests a potential supply sufficient to last at least a century, based on declining world usage rates.

Demand – The breakdown of domestic consumption of mercury by particular categories is no longer available, but the data as of 1997 showed that chlorine and caustic soda accounted for 46% of US mercury consumption, followed by wiring devices and switches (17%), dental equipment (12%), electrical lighting (8%), and measuring control instruments (7%). Substitutes for mercury include lithium and composite ceramic materials.

Trade – US foreign trade in mercury is small. US imports of mercury in 2002 more than doubled to 209 metric tons from 100 metric tons in 2001. At the same time, the US exported 201 metric tons of mercury in 2002, up from 108 metric tons in 2000. The imports were mostly from Chile and Peru. Exports are scattered, but India and the Netherlands were generally the largest takers.