Oh , a chemical element. The chemical symbol Nb, atomic number 41, atomic weight 92.90638, belongs to the periodic system VB. 1801 British C. Hatchett separated from the niobium oxide of iron ore a new element and the element is designated columbium (in translation columbium). In 1802, Sweden AG Erkeberg found another new element, tantalum, in the coltan. Because these two elements are very similar in nature, many people think they are the same element. In 1844, Deutsche H. Roze studied a lot of coltan and coltan, and separated the two elements to clarify the truth. The content of strontium in the earth's crust is 0.002%. The main minerals are lanthanum ore [(Fe,Mn)(Nb,Ta) 2 O 6 ], pyrochlore [(Ca,Na) 2 (Nb,Ta,Ti) 2 O 6 (OH, F)] and dilute black gold ore, fergusonite ore, tantalite, niobium, titanium, calcium, cerium ore.
Rhodium is an off-white metal with a melting point of 2468 ° C, a boiling point of 4742 ° C and a density of 8.57 g / cm 3 . At room temperature, helium is stable in air, and is not completely oxidized when it is red hot in oxygen. It is directly combined with sulfur, nitrogen and carbon at high temperature, and can form alloys with titanium, zirconium , hafnium and tungsten. Does not interact with inorganic acids or bases, is not soluble in aqua regia, but soluble in hydrofluoric acid. The oxidation state of ruthenium is -1, +2, +3, +4 and +5, with the most stable compound at +5.
First, the production of cockroaches
The metal ruthenium can be prepared by electrolytically melting potassium hexafluoroantimonate, or can be obtained by reducing sodium hexafluoroantimonate or metal aluminum to reduce bismuth pentoxide. Pure niobium is used in the electron tube to remove residual gas. The antimony in steel can improve the oxidation resistance of steel at high temperature and improve the welding performance of steel. Tantalum is also used in the manufacture of high temperature cermets.
Second, the use of cockroaches
Bismuth is a rare high melting point metal with a melting point of up to 2,400 degrees Celsius. The excellent properties of a metal can often be "transplanted" into another metal. The addition of strontium as an alloying element to the steel can increase the high temperature strength of the steel and improve the processing performance.铌, 钽 and a series of metals such as tungsten, molybdenum , vanadium , nickel , cobalt, etc., the "heat-strength alloy" can be used as a supersonic jet aircraft and rocket, missile and other structural materials. At present, scientists have begun to turn their attention to sputum and sputum when developing new high-temperature structural materials; many high-temperature, high-strength alloys have participated in this pair of twin brothers.
Cemented carbide made of tantalum and niobium carbide as a matrix has high strength and resistance to pressure, abrasion and corrosion. Among all the hard compounds, the hardness of tantalum carbide is the highest. The tool made of tantalum carbide hard alloy can withstand the high temperature below 3.8 Baidu, the hardness can be compared with diamond , and the service life is longer than tungsten carbide.
Third, the superconducting application of bismuth
There are many elements with superconducting properties, and helium is one of the highest critical temperatures. The alloy made of niobium has a critical temperature of up to 18.5 to 21 K absolute temperature and is the most important superconducting material at present. People have done such an experiment: put a metal ring that is cold to superconducting state, put current on it and then disconnect the current, then close the whole instrument to keep it cool. After two and a half years, people turned the instrument on and found that the current in the ankle ring was still flowing, and the current was almost exactly the same as when it was energized! It can be seen from this experiment that the superconducting material hardly loses current. If a superconducting cable is used for power transmission, since it has no resistance, there is no energy loss when the current passes, so the transmission efficiency will be greatly improved.
A high-speed maglev train has been designed with superconducting magnets mounted on its wheels so that the entire train can float about ten centimeters in orbit. In this way, there will be no friction between the train and the track, reducing the resistance to advance. A series of maglev trains carrying hundreds of people can achieve speeds of more than 500 kilometers per hour with a driving force of 100 horsepower.
Up to 20 kilometers with a niobium tin tape wound on a diameter of 1.5 meters of the rim, the winding can produce a strong and stable magnetic field, enough to raise one hundred twenty-two kg of weight, and it Suspended in the magnetic field space. If this kind of magnetic field is used in the thermonuclear fusion reaction and the powerful thermonuclear fusion reaction is controlled, it is possible to provide us with a large amount of almost endless cheap electricity. Not long ago, a DC generator was made from a titanium-titanium superconducting material. It has many advantages, such as small size, light weight, and low cost. Compared with ordinary generators of the same size, it generates a hundred times more electricity.
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