Niobium was discovered in England in 1801 by C.M. Hatchett, who called it Columbium due to the American origin of its ore samples. The isolation of niobium was performed in Germany by H.Rose in 1844; he isolated it from the tantalum and named it niobium after Niobi, a daughter of the legendary King Tantalus. The name niobium was officially designated by the International Union of Pureand Applied Chemistry in 1951. Niobium was acquired until the early 60’s, as a by-product, mainly from the columbite-tantalite’s treatment, which were scarce ores of erroneous occurrence. As aresult, it was very expensive and used restrictedly to a type of stainless steel and some super alloys. Its discovery of expressive reserves of pyrochore (niobium ore) in Araxá, MG, in early 50’s and itstechnical practicability took place simultaneously in the USA and England, through the development of high strengthen and low alloy steels. These two events molded the profile of metal consumption, inwhich the predominance of metallurgical sector is noticed.
Niobium, light silver refractory metal, ductile, atomic number 41, has been largely applied in modern engineering. Its use increased fromsmall amounts, in the first half of this century, to over 10 tons a year in the early 80’s. There are many and diversified reasons for the growth of its use. However, it is believed that in allapplications, from steel to superconductors. Its crescent acceptance is based on three important reasons: versatility, economical advantages and the availability for several centuries.
Niobium is versatile:its current use varies from structural steels and steels used in the automobile industry to materials for jet engines and gas turbines. It still finds important applications in metallic alloys forthe chemical industries, in stainless steels and in a variety of metals resistant to heat and corrosion. For instance, each 100 km. of 1,4 m diameter gas pipes, built with high strengthen metal sheets...
Ler documento completo
Por favor, assinar para o acesso.