Welsbach

Gr. prasios, green, and didymos, twin) In 1841 Mosander extracted the rare earth didymia from lanthana in 1879, Lecoq de Boisbaudran isolated a new earth, samaria, from didymia obtained from the mineral samarskite. Six years later, in 1885, von Welsbach separated didymia into two others, praseodymia and neodymia, which gave salts of different colors. As with other rare earths, compounds of these elements in solution have distinctive sharp spectral absorption bands or lines, some of which are only a few Angstroms wide. 

Gr. neos, new, and didymos, twin) In 1841, Mosander, extracted from cerite a new rose-colored oxide, which he believed contained a new element. He named the element didymium, as it was an inseparable twin brother of lanthanum. In 1885 von Welsbach separated didymium into two new elemental components, neodymia and praseodymia, by repeated fractionation of ammonium didymium nitrate. While the free metal is in misch metal, long known and used as a pyrophoric alloy for light flints, the element was not isolated in relatively pure form until 1925. Neodymium is present in misch metal to the extent of about 18%. It is present in the minerals monazite and bastnasite, which are principal sources of rare-earth metals. 

Ytterby, village in Sweden) Marignac in 1878 discovered a new component, which he called ytterbia, in the earth then known as erbia. In 1907, Urbain separated ytterbia into two components, which he called neoytterbia and lutecia. The elements in these earths are now known as ytterbium and lutetium, respectively. These elements are identical with aldebaranium and cassiopeium, discovered independently and at about the same time by von Welsbach. 

The minerals on which the work was performed during the nineteenth century were indeed rare, and the materials isolated were of no interest outside the laboratory. By 1891, however, the Austrian chemist C. A. von Welsbach had perfected the thoria gas mantle to improve the low luminosity of the coal-gas flames then used for lighting. Woven cotton or artificial silk of the required shape was soaked in an aqueous solution of the nitrates of appropriate metals and the fibre then burned off and the nitrates converted to oxides. A mixture of 99% ThOz and 1% CeOz was used and has not since been bettered. CeOz catalyses the combustion of the gas and apparently, because of the poor thermal conductivity of the ThOz, particles of CeOz become hotter and so brighter than would otherwise be possible. The commercial success of the gas mantle was immense and produced a worldwide search for thorium. Its major ore is monazite, which rarely contains more than 12% ThOz but about 45% LnzOz. Not only did the search reveal that thorium, and hence the lanthanides, are more plentiful than had previously been thought, but the extraction of the thorium produced large amounts of lanthanides for which there was at first little use. 

Praseodymium, Pr C. A. von Welsbach 1885 Greek rrpaoio -l-SiSup.o praseos -I- didymos, leek green -1- twin... 

Auer-brenner) m. Welsbach burner, -licht) n. Welsbach light, -metall) n. Welsbach metal (pyrophoric cerium alloy), auf) prep, on, upon, in, at about into, to. 

Austrian chemist Carl Auer (Ereiherr von Welsbach) invents the Welsbach mantle, tripling the output of kerosene lamps and... 

Ozone was generated using a Welsbach ozonator at a total gas flow... 

A Welsbach T-816 Ozonator purchased from the Welsbach Corporation, Philadelphia, Pennsylvania, was used. The oxygen stream was dried by passage through dry silica gel and molecular sieves and then introduced into the ozonator with the operating voltage set at 115 V., the gas pressure at 8 p.s.i.g., and the gas flow rate at 1 1. per minute. The resulting ozone flow rate was 0.00245 mole per minute, as determined by titration of a potassium iodide trap. ... 

Carl Auer von Welsbach (1858-1929) separated praseodymium and neodymium. 

Georges Urbain (1872-1938) and Carl Auer von Welsbach confirmed the existence of the element in 1907. 

Neodymium (Nd, [Xe]4/46.s 2), name and symbol after the Greek words veo< + L upoq (neos + didymos, new twin). Discovered (1885) by Carl F. Auer von Welsbach. 

Lutetium (Lu, [Xe]4/ 145 / 6.v2), name and symbol after the Latin word Lutetia (Paris). Discovered (1907) by Georges Urbain and Carl Auer von Welsbach. Silvery white metal. 

Neodymium - the atomic number is 60 and the chemical symbol is Nd. The name was originally neodidymium and was later shortened to neodymium, which is derived from the Greek neos for new and didymos for twin . It was discovered by the Swedish surgeon and chemist Carl Gustav Mosander in 1841, who called it didymium (or twin) because of its similarity to lanthanium which he had previously discovered two years earlier. In 1885, the Austrian chemist Carl Auer von Welsbach separated didymium into two elements. One of which he called neodymium (or new twin). 

In 1885 Carl Auer Baron von Welsbach (1858-1929) separated the oxides of two similar elements from didymium. He named one praseodymium from the Greek word prasios, which means green or the green twin, and he named the other element neodymium, which is derived from new and dymium and means new twin. ... 

In 1885 Carl Auer Baron van Welsbach separated a common rare-earth called didymium into two distinct rare-earths. One he called green didymia (praseodymium) and the other he named new didymia (neodymium). The green color of green didymia (praseodymium) is caused by contamination of iron. 

Lutetium Lu 1907-08 (Paris, France) and (Vienna, Austria) Georges Urbain (French) and Carl von Welsbach (Austrian) 302... 

It is obvious that the narrow band thermoluminescence 8, 9) influenced Carl Auer von Welsbach in developing his mantle between 1884 and 1892, but as discussed in the next chapter, the optimized conditions for white gas-light rather involve another t cpe of excited states of cerium(IV). On the other hand, the cathodo-luminescence in narrow bands discovered by William Crookes and carefully studied by Urbain [12) corresponds to internal transitions in the partly filled shell. Thus, the excited state of 4/ europium(III) produces the red emission (important for colour television) in the orthovanadate [13) Yi Eux VO 4 and in the oxysulphide (74) by transitions to " Fz, and Fq. Certain... 

Austrian mineralogist Carl Auer von Welsbach Found in the ores bastnasite and in monazite, which contain all of the natural rare earth elements alloy used in the auto and aircraft industries. 

Austrian mineralogist Carl Auer von Welsbach Highly magnetic and used in many commercial applications can be used to detect counterfeit paper money by showing whether the printing ink is magnetic. 

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