Rio Tinto Borax Mine
Encyclopedia
The Rio Tinto Borax Mine (also known as the U.S. Borax Boron Mine) in Boron, CA is California
's largest open-pit mine and the largest borax
mine in the world, producing nearly half the world's borates. It is operated by the Rio Tinto Group
.
The borax
deposit here was discovered in 1913, by Dr. John K. Sukow, who when drilling for water found a deposit of what he believed to by gypsum
, but further testing revealed that it was the colemanite
form of borax
. Francis Marion "Borax" Smith quickly bought the claim for his Pacific Coast Borax Company
. Mining at the site by shafts began in the 1920s. Pacific Coast Borax later became U.S. Borax, which subsequently opened the current open pit mine in 1957. U.S. Borax was later acquired by Rio Tinto Group
, which continues to operate the mine today.
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
's largest open-pit mine and the largest borax
Borax
Borax, also known as sodium borate, sodium tetraborate, or disodium tetraborate, is an important boron compound, a mineral, and a salt of boric acid. It is usually a white powder consisting of soft colorless crystals that dissolve easily in water.Borax has a wide variety of uses...
mine in the world, producing nearly half the world's borates. It is operated by the Rio Tinto Group
Rio Tinto Group
The Rio Tinto Group is a diversified, British-Australian, multinational mining and resources group with headquarters in London and Melbourne. The company was founded in 1873, when a multinational consortium of investors purchased a mine complex on the Rio Tinto river, in Huelva, Spain from the...
.
The borax
Borax
Borax, also known as sodium borate, sodium tetraborate, or disodium tetraborate, is an important boron compound, a mineral, and a salt of boric acid. It is usually a white powder consisting of soft colorless crystals that dissolve easily in water.Borax has a wide variety of uses...
deposit here was discovered in 1913, by Dr. John K. Sukow, who when drilling for water found a deposit of what he believed to by gypsum
Gypsum
Gypsum is a very soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. It is found in alabaster, a decorative stone used in Ancient Egypt. It is the second softest mineral on the Mohs Hardness Scale...
, but further testing revealed that it was the colemanite
Colemanite
Colemanite is a borate mineral found in evaporite deposits of alkaline lacustrine environments. Colemanite is a secondary mineral that forms by alteration of borax and ulexite....
form of borax
Borax
Borax, also known as sodium borate, sodium tetraborate, or disodium tetraborate, is an important boron compound, a mineral, and a salt of boric acid. It is usually a white powder consisting of soft colorless crystals that dissolve easily in water.Borax has a wide variety of uses...
. Francis Marion "Borax" Smith quickly bought the claim for his Pacific Coast Borax Company
Pacific Coast Borax Company
The Pacific Coast Borax Company was a United States mining company founded in 1890 by the American borax magnate Francis "Borax" Smith, the "Borax King".-History:...
. Mining at the site by shafts began in the 1920s. Pacific Coast Borax later became U.S. Borax, which subsequently opened the current open pit mine in 1957. U.S. Borax was later acquired by Rio Tinto Group
Rio Tinto Group
The Rio Tinto Group is a diversified, British-Australian, multinational mining and resources group with headquarters in London and Melbourne. The company was founded in 1873, when a multinational consortium of investors purchased a mine complex on the Rio Tinto river, in Huelva, Spain from the...
, which continues to operate the mine today.