In the west, the understanding of aluminum began in17th century. German chemist Shtal (1660- 1734) first noticed alum (K2SO4? Aluminum sulfate? 24H2O) contains a substance very different from ordinary metals. His student Magraff (1709-1782) separated Al2O3ina from alum at 1754, and determined that it was different from calcium oxide.
1800, after the Italian physicist Volta invented the battery, both British chemist David and Swedish chemist Betzelius tried to separate aluminum from bauxite by electrolysis, but both failed. On the other hand, David named this unattainable metal aluminum, which comes from Latin aluminum. In medieval Europe, this term was a generic term for convergent alum, which refers to the mordant for dyeing cotton. We transliterated it into aluminum from its second syllable.
1825, Danish pharmacist hans christian oersted (1777- 185 1) published the process of manufacturing aluminum: chlorine gas passes through the mixture of red-hot charcoal and alumina to obtain aluminum trichloride, and then it is mixed with potassium amalgam and heated to obtain potassium chloride and aluminum amalgam, and then the aluminum amalgam is stored in a closed place.
1827 german chemist Friedrich w? Hler, 1800- 1882) repeated Oster's experiment. He made aluminum trichloride according to Oster's method, then replaced aluminum with potassium, and then put aluminum chloride and metal potassium in a crucible, sealed, heated and reacted violently. After the crucible is cooled, there is gray aluminum powder in the contents.
By 1854, the French chemist Henri Tien St. Clair de Ville (1818-1881) reduced aluminum chloride with sodium instead of potassium. He first extracted alumina from iron-bearing bauxite, and then mixed aluminum chloride with charcoal and salt to react with chlorine to produce NaCl? AlCl3 double salt, in which AlCl3 is reduced by sodium to produce aluminum ingots.
At that time, aluminum was more expensive than iron and copper because of its high preparation cost and troublesome extraction. For a time, aluminum was a commodity in jewelry stores and a treasure of emperors and nobles. The French emperor Charles Louis Napolé on Bonaparte used aluminum forks at banquets, and the Thai king used aluminum chains. 1855, at the World Commodities Fair held in Paris, a small piece of aluminum was placed next to the jewelry, and the label read: "Silver from clay". Until 1884, the monument to George Washington, the first president of the United States (1732- 1799) was built, and a decorative pyramid weighing 6 pounds (about 2000 grams) was erected on the monument, which was made of aluminum. 1889 Russian chemist Mendeleev (дмитрийивановичмн)
188 1 year, an Englishman James fern Webster obtained a patent for the industrial production of aluminum. He built a factory near Birminghan, producing about 20 tons a week. 1883, he sent his products to Kolkata International Expo in India and won two gold medals, but he kept the production secret.
In 1950s, some scientific magazines and newspapers published in China published articles about the first production of aluminum by working people in ancient China. The thing is, 1956, Chinese archaeologists excavated the tomb of Zhou Chu (242-297), a general of the Jin Dynasty, in Yixing County, Jiangsu Province, and found more than 20 metal plates with hollow patterns scattered in the mud. After analysis by scientists from the Department of Chemistry of Nanjing University, the Institute of Applied Physics of Chinese Academy of Sciences and the Department of Chemical Engineering of Tsinghua University, it is determined that one or two of them are copper-aluminum alloys. It contains 85% aluminum, 10% copper and 5% manganese, so some researchers in the history of science judged that aluminum was already used by our ancestors before 297 AD, or before the 3rd century AD, so some people published articles on this view in newspapers and periodicals.
There are also some people who hold different opinions. Why is it that only one or two ornaments analyzed contain aluminum, while the others are all silver? If aluminum was already produced in the Jin Dynasty, why hasn't it been discovered since the Jin Dynasty? It has even been suggested that it is impossible for China's science and technology to reduce aluminum from chemical compounds in the 3rd century, and this issue should be considered realistically. Finally, Xia Nai, an archaeologist, published the article "Re-appraisal of the Metal Belt Unearthed from the Tomb of the Jin Dynasty" in the No.4 issue of Archaeology 1972, arguing that the small pieces of aluminum found in the tomb of the Jin Dynasty were suspected of being mixed with later generations, and could never be used as physical evidence of the existing metal aluminum in the Jin Dynasty.
Modern aluminum was successfully created by two college students through experimental research in 1886.
One of these two college students is Charles Martin Hal (1863- 19 14), who is a chemistry student at Oberlin University in Ohio. He was influenced by his teacher Jouett (1844). ) professor's encouragement, looking for ways to make aluminum by electrolysis. Jouett studied with Willer in Germany and was interested in aluminum production.
From 65438 to 0884, Hall began to do experiments in Jouett's laboratory. He made his own battery, made aluminum fluoride from dangerous hydrofluoride, and then electrolyzed the aqueous solution of aluminum fluoride to get hydrogen and aluminum hydroxide.
1In June, 885, after graduating from Hall University, he continued to conduct experiments in the shed where firewood was piled at home. With the help of her sister Julia Hall, who studied chemistry, Hall switched to molten cryolite (AlF3? 3NaF) as a solvent, alumina was dissolved and electrolyzed. From February 9th, 1886, many experiments were carried out until February 23rd, when a silvery white metal ball appeared on the cathode, which was confirmed as aluminum by hydrochloric acid test.
Hall knows that a major discovery or invention needs indirect evidence. Immediately after the success of 1886, he wrote a letter to his brother (a government official) describing the scientific and technological information he found. This letter later proved in law that he gave priority to the discovery of aluminum by electrolysis.
Vinay Kumar, Linda millers Kerr. Charles Martin Hal and the great aluminum revolution. Journal of Chemical Education,1987,64 (8).
65438+Generators appeared in 1960s in 2009, which enabled large-scale electrolytic production of aluminum. 1888, Hall began to invest in small-scale industrial production with the support of the industrial giant Captain Alfred Hunt. 1889 established Alcoa, and 1889 obtained the patent of aluminum production process on April 2. By 1907, Alcoa has owned several mines producing alumina and three factories producing electrolytic aluminum. The price of aluminum dropped sharply from $500/lb to $8/lb for 1884, $5/lb for 1886, $0/888+0/lb for 1893 and $0.70/lb for 65433. According to the modern industrial manufacturing method of aluminum created by Hall, this metal has been widely used in family, industry and transportation. Figure 25- 1 is a modern aluminum electrolysis furnace.
In the process of electrolysis, alumina is added on time, and the generated metallic aluminum is released. The cryolite used is prepared by dissolving aluminum hydrofluoride and sodium carbonate in hydrofluoric acid;
Natural iron-bearing bauxite usually contains 40%~60% Al2O3, and the rest are impurities such as SiO2 and Fe2O3. Impurities must be removed by chemical methods, that is, when bauxite is heated with alkali, alumina will become aluminate and dissolve, and then carbon dioxide gas will be introduced to precipitate aluminum hydroxide.
Another college student who founded the electrolytic legal system was Paul Louis Toussaint Herro of French Saint-Balber College (1863- 19 14). From the age of 15, he read De Ville's theory about aluminum production and got the idea of aluminum production. Later, he got the legacy of a leather factory, which installed a generator. He began to electrolyze various aluminum compounds, and finally came up with the same electrolytic aluminum production method as Hall, only two months later than Hall. He just obtained the invention patent and transferred it to others, and he did not participate in industrial production himself.
19 1 1 year, American Chemical Society and Chemical Engineering Society awarded Hall a Bochen Medal (in memory of British industrial chemist Bochen). Elliott traveled across the ocean to the United States to congratulate Hall. What a coincidence, these two college students were born and died in the same year, and successfully created the method of electrolytic aluminum production in the same year.
Hall never married. After his death, he left a million dollars to donate to his alma mater. In memory of his mother, the campus built an auditorium for Hall. Today, a full-body aluminum statue of a young Hall (Figure 25-2) still stands on the campus of Oberlin University, leaving people to pay their respects.