Charles Martin Hall
Charles Martin Hall
|Born||December 6, 1863|
|Died||December 27, 1914 51) (aged|
|Family||Julia Brainerd Hall (sister)|
|Significant advance||Hall–Héroult process|
|Awards||Perkin Medal (1911)|
Charles Martin Hall (December 6, 1863 – December 27, 1914) was an American inventor, businessman, and chemist. He is best known for his invention in 1886 of an inexpensive method for producing aluminum, which became the first metal to attain widespread use since the prehistoric discovery of iron. He was one of the founders of Alcoa. Alfred E. Hunt, together with Charles Hall and a group of five other individuals – his[ whose? ] partner at the Pittsburgh Testing Laboratory, George Hubbard Clapp; his chief chemist, W. S. Sample; Howard Lash, head of the Carbon Steel Company; Millard Hunsiker, sales manager for the Carbon Steel Company; and Robert Scott, a mill superintendent for the Carnegie Steel Company – raised $20,000 to launch the Pittsburgh Reduction Company, which was later renamed Aluminum Company of America and shortened to Alcoa.
Charles Martin Hall was born to Herman Bassett Hall and Sophronia H. Brooks on December 6, 1863, in Thompson, Ohio.Charles' father, Herman, graduated from Oberlin College in 1847, and studied for three years at the Oberlin Theological Seminary, where he met his future wife, Sophronia Brooks. They married in 1849, and the next ten years were spent in missionary work in Jamaica, where the first five of their eight children were born. They returned to Ohio in 1860, after the outbreak of the Civil War forced the closing of foreign missions. Charles Hall had two brothers and five sisters; one brother died in infancy. One of his sisters was chemist Julia Brainerd Hall (1859–1925), who helped him in his research.
Hall began his education at home, and was taught to read at an early age by his mother. [ citation needed ]At the age of six, he was using his father's 1840s college chemistry book as a reader. At age 8, he entered public school, and progressed rapidly.
Hall's family moved to Oberlin, Ohio, in 1873. He spent three years at Oberlin High School, and a year at Oberlin Academy in preparation for college. [ page range too broad ]During this time, he demonstrated his aptitude for chemistry and invention, carrying out experiments in the kitchen and the woodshed attached to his house. In 1880, at the age of 16, he enrolled at Oberlin College.
In his second term, Hall attended, with considerable interest, Oberlin Professor Frank Fanning Jewett's lecture on aluminum; it was here that Jewett displayed the sample of aluminum he had obtained from Friedrich Wöhler at Göttingen, and remarked, "if anyone should invent a process by which aluminum could be made on a commercial scale, not only would he be a benefactor to the world, but would also be able to lay up for himself a great fortune". [ page range too broad ]
Hall's initial experiments in finding an aluminum reduction process were in 1881. He attempted, unsuccessfully, to produce aluminum from clay by smelting with carbon in contact with charcoal and potassium chlorate. He next attempted to improve the electrolytic methods previously established by investigating cheaper methods to produce aluminum chloride, again unsuccessfully. In his senior year, he attempted to electrolyze aluminum fluoride in water, but was unable to produce aluminum at the cathode.
In 1884, after setting up a homemade coal-fired furnace and bellows in a shed behind the family home, Hall again tried to find a catalyst that would allow him to reduce aluminum with carbon at high temperatures: "I tried mixtures of alumina and carbon with barium salts, with cryolite, and with carbonate of sodium, hoping to get a double reaction by which the final result would be aluminum. I remember buying some metallic sodium and trying to reduce cryolite, but obtained very poor results. I made some aluminum sulphide but found it very unpromising as a source of aluminum then as it has been ever since". [ page range too broad ]
Hall had to fabricate most of his apparatus and prepare his chemicals, and was assisted by his older sister Julia Brainerd Hall.The basic invention, which he discovered on February 23, 1886, involves passing an electric current through a bath of alumina dissolved in cryolite, which results in a puddle of aluminum forming in the bottom of the retort. On July 9, 1886, Hall filed for his first patent. This process was also discovered at nearly the same time by the Frenchman Paul Héroult, and it has come to be known as the Hall–Héroult process.
After failing to find financial backing at home, Hall went to Pittsburgh, where he made contact with noted metallurgist Alfred E. Hunt. They formed the Reduction Company of Pittsburgh, which opened the first large-scale aluminum production plants. The Reduction Company later became the Aluminum Company of America, then Alcoa. Hall was a major stockholder, and became wealthy.
The Hall–Héroult process eventually resulted in reducing the price of aluminum by a factor of 200, making it affordable for many practical uses. By 1900, annual production reached about 8,000 tons. Today, more aluminum is produced than all other non-ferrous metals combined.[ citation needed ]
Hall is sometimes suggested to be the originator of the American spelling of "aluminum", but that spelling was used briefly by Humphry Davy in the early 1800s and was the spelling in Noah Webster's Dictionary of 1828. "Aluminium" was used widely in the United States until 1895 or 1900, and "aluminum" was not officially adopted by the American Chemical Society until 1925.Hall's early patents use the spelling "aluminium". In the United Kingdom and other countries using British spelling, only the spelling "aluminium" is now used. The spelling in virtually all other languages is analogous to the "-ium" ending.
Hall continued his research and development for the rest of his life and was granted 22 US patents, most on aluminum production. He served on the Oberlin College Board of Trustees. He was vice-president of Alcoa until his death.[ citation needed ]
Hall died, unmarried and childless, on December 27, 1914, twenty-one days after he had reached the age of 51, in Daytona, Florida. He was buried in Westwood Cemetery in Oberlin.He died the same year as Héroult, and they both were born the same year.
In his last will and testament, Hall left the vast majority of his fortune to charity. His generosity contributed to the establishment of the Harvard-Yenching Institute, a leading foundation dedicated to advancing higher education in Asia in the humanities and social sciences.
Hall won the Perkin Medal, the highest award that the American section of the Society of Chemical Industry bestows, in 1911.In 1997, the production of aluminum metal by electrochemistry discovered by Hall was designated as a National Historic Chemical Landmark by the American Chemical Society.
Hall eventually became one of Oberlin College's most prominent benefactors, and an aluminum statue of him exists on the campus.Because of its light weight, Hall's statue was once known for its frequent changes of location, often due to student pranks. Today the statue is glued to a large granite block and sits more permanently on the second floor of Oberlin's science center, where students continue to decorate Hall with appropriate trappings on holidays and other occasions.
The Jewett home is preserved in Oberlin as the Oberlin Heritage Center. The center features an exhibit called Aluminum: The Oberlin Connection, which includes a re-creation of Hall's 1886 woodshed experiment.The Hall House is also preserved in Oberlin, although the woodshed was demolished long ago.
Aluminium is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has a great affinity towards oxygen, and forms a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver, both in its color and in its great ability to reflect light. It is soft, non-magnetic and ductile. It has one stable isotope, 27Al; this isotope is very common, making aluminium the twelfth most common element in the Universe. The radioactivity of 26Al is used in radiodating.
Paul (Louis-Toussaint) Héroult was a French scientist. He was the inventor of the aluminium electrolysis and developed the first successful commercial electric arc furnace. He lived in Thury-Harcourt, Normandy.
In chemistry and manufacturing, electrolysis is a technique that uses direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. The voltage that is needed for electrolysis to occur is called the decomposition potential. The word "lysis" means to separate or break, so in terms, electrolysis would mean either "breakdown of electricity" or "breakdown via electricity".
The Hall–Héroult process is the major industrial process for smelting aluminium. It involves dissolving aluminium oxide (alumina) in molten cryolite, and electrolysing the molten salt bath, typically in a purpose-built cell. The Hall–Héroult process applied at industrial scale happens at 940–980 °C and produces 99.5–99.8% pure aluminium. Recycled aluminum requires no electrolysis, thus it does not end up in this process. This process contributes to climate change through the emission of carbon dioxide in the electrolytic reaction.
Cryolite (Na3AlF6, sodium hexafluoroaluminate) is an uncommon mineral identified with the once-large deposit at Ivittuut on the west coast of Greenland, depleted by 1987.
The Bayer process is the principal industrial means of refining bauxite to produce alumina (aluminium oxide) and was developed by Carl Josef Bayer. Bauxite, the most important ore of aluminium, contains only 30–60% aluminium oxide (Al2O3), the rest being a mixture of silica, various iron oxides, and titanium dioxide. The aluminium oxide must be purified before it can be refined to aluminium metal.
Alcoa Corporation is an American industrial corporation. It is the world's eighth largest producer of aluminum, with corporate headquarters in Pittsburgh, Pennsylvania. Alcoa conducts operations in 10 countries. Alcoa is a major producer of primary aluminum, fabricated aluminum, and alumina combined, through its active and growing participation in all major aspects of the industry: technology, mining, refining, smelting, fabricating, and recycling.
Industrial processes are procedures involving chemical, physical, electrical or mechanical steps to aid in the manufacturing of an item or items, usually carried out on a very large scale. Industrial processes are the key components of heavy industry.
The Castner process is a process for manufacturing sodium metal by electrolysis of molten sodium hydroxide at approximately 330 °C. Below that temperature, the melt would solidify; above that temperature, the molten sodium would start to dissolve in the melt.
The Wöhler process was one of the first routes for producing aluminium metal. It involves the reduction of anhydrous aluminium chloride with potassium, produced powdered aluminium:
Carl Josef Bayer was an Austrian chemist who invented the Bayer process of extracting alumina from bauxite, essential to this day to the economical production of aluminium.
Aluminum carbide, chemical formula Al4C3, is a carbide of aluminum. It has the appearance of pale yellow to brown crystals. It is stable up to 1400 °C. It decomposes in water with the production of methane.
Alfred Ephraim Hunt was a 19th-century American metallurgist and industrialist best known for founding the company that would eventually become Alcoa, the world's largest producer and distributor of aluminum.
The Oberlin Heritage Center is a non-profit 501(c)(3) organization, governed by an 18-member Board of Trustees. The organization is funded by memberships, annual fund contributions, investments, grants, fund-raising projects and planned gifts. Over 700 members hail from Oberlin and elsewhere in Lorain County, as well as from across the country.
George Hubbard Clapp (1858–1949) was an American pioneer in the aluminum industry and also a numismatist.
Aluminium smelting is the process of extracting aluminium from its oxide, alumina, generally by the Hall-Héroult process. Alumina is extracted from the ore bauxite by means of the Bayer process at an alumina refinery.
The Electric Smelting and Aluminum Company, founded as Cowles Electric Smelting and Aluminum Company, and Cowles Syndicate Company, Limited, formed in the United States and England during the mid-1880s to extract and supply valuable metals. Founded by two brothers from Ohio, the Cowles companies are remembered for producing alloys in quantity sufficient for commerce. Their furnaces were electric arc smelters, one of the first viable methods for extracting metals.
The Hoopes process is a metallurgical process, used to obtain the aluminium metal of very high purity. The process was patented by William Hoopes, a chemist of the Aluminum Company of America (ALCOA) in 1925.
Julia Brainerd Hall was the sister of American scientist Charles Martin Hall. She supported him in his discovery of the Hall process for extracting aluminium from its ore. She was also a still-life painter, who exhibited at the Edgar Adams Gallery in Cleveland.
Aluminium metal is very rare in native form, and the process to refine it from ores is complex, so for most of human history it was unknown. However, the compound alum has been known since the 5th century BCE and was used extensively by the ancients for dyeing. During the Middle Ages, its use for dyeing made it a commodity of international commerce. Renaissance scientists believed that alum was a salt of a new earth; during the Age of Enlightenment, it was established that this earth, alumina, was an oxide of a new metal. Discovery of this metal was announced in 1825 by Danish physicist Hans Christian Ørsted, whose work was extended by German chemist Friedrich Wöhler.
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