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Djalma Guimarães
Djalma Guimarães (November 5, 1894 – October 10, 1973), was a pioneer Brazilian geochemistry, geochemist. He was Professor Emeritus at the Ouro Preto Mining School (now part of the Federal University of Ouro Preto) and at the Federal University of Minas Gerais, in Belo Horizonte. At both institutions, he taught geological sciences for over 35 years. He was a grandson of Councillor Joaquim Caetano da Silva Guimarães and of the Senator Manoel Teixeira da Costa. Guimarães was brought up in a family which had produced such Brazilian writers as Bernardo Guimarães and Alphonsus de Guimaraens. He was also a nephew of scientists Pandiá Calógeras and Paul Ferrand. Career Guimarães' interest in mineralogy, petrography and geology was inspired during his student years at the Ouro Preto Mining School by the lessons and assignments given by Professor Costa Sena. He graduated in 1919 from this school with the title of Civil, Mining and Metallurgical Engineer. His first prize was a stud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santa Luzia, Minas Gerais
Santa Luzia is a Brazilian municipality located in the state of Minas Gerais. The city belongs to the mesoregion Metropolitana de Belo Horizonte and to the microregion of Belo Horizonte. Its population in 2020 was 220,444. See also * List of municipalities in Minas Gerais This is a list of the municipalities in the state of Minas Gerais (MG), located in the Southeast Region of Brazil. Minas Gerais is divided into 853 municipalities, which are grouped into 66 microregions, which are grouped into 12 mesoregions. ... References Municipalities in Minas Gerais {{MinasGerais-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petrography
Petrography is a branch of petrology that focuses on detailed descriptions of rocks. Someone who studies petrography is called a petrographer. The mineral content and the textural relationships within the rock are described in detail. The classification of rocks is based on the information acquired during the petrographic analysis. Petrographic descriptions start with the field notes at the outcrop and include macroscopic description of hand specimens. The most important petrographer's tool is the petrographic microscope. The detailed analysis of minerals by optical mineralogy in thin section and the micro-texture and structure are critical to understanding the origin of the rock. Electron microprobe or atom probe tomography analysis of individual grains as well as whole rock chemical analysis by atomic absorption, X-ray fluorescence, and laser-induced breakdown spectroscopy are used in a modern petrographic lab. Individual mineral grains from a rock sample may also be analyze ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brazilian Geochemists
Brazilian commonly refers to: * Something of, from or relating to Brazil * Brazilian Portuguese, the dialect of the Portuguese language used mostly in Brazil * Brazilians, the people (citizens) of Brazil, or of Brazilian descent Brazilian may also refer to: Sports * Brazilian football, see football in Brazil * Brazilian jiu-jitsu, a martial art and combat sport system *''The Brazilians'', a nickname for South African football association club Mamelodi Sundowns F.C. due to their soccer kits which resembles that of the Brazilian national team Other uses * Brazilian waxing, a style of Bikini waxing * Brazilian culture, describing the Culture of Brazil * "The Brazilian", a 1986 instrumental by Genesis * Brazilian barbecue, known as churrasco * Brazilian cuisine See also * ''Brasileiro ''Brasileiro'' is a 1992 album by Sérgio Mendes and other artists including Carlinhos Brown which won the 1993 Grammy Award for Best World Music Album. Track listing # "Fanfarra" (Carlinhos Brown) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranmicrolite
Microlite was once known as a pale-yellow, reddish-brown, or black isometric mineral composed of sodium calcium tantalum oxide with a small amount of fluorine. Its chemical formula is. Today it is a name of a group of oxide minerals of a similar stoichiometry having tantalum prevailing over titanium and niobium. The microlite group belongs to a large pyrochlore supergroup that occurs in pegmatites and constitutes an ore of tantalum. It has a Mohs hardness of 5.5 and a variable specific gravity of 4.2 to 6.4. It occurs as disseminated microscopic subtranslucent to opaque octahedral crystals with a refractive index of 2.0 to 2.2. Microlite is also called djalmaite, but both names are now obsolete. "Microlite" occurs as a primary mineral in lithium-bearing granite pegmatites, and in miarolitic cavities in granites. Association minerals include: albite, lepidolite, topaz, beryl, tourmaline, spessartine, tantalite and fluorite. "Microlite" was first described in 1835 for an occurrenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tantalate
Tantalate is an tantalum-containing anion or a salt of such an anion. A commercially important example is heptafluorotantalate (TaF72−) and its potassium salt (K2TaF7). : Many oxides of tantalum are called tantalates. They are viewed as derivatives of "tantalic acid", hypothetic compounds with the formulas Ta2O5·nH2O or HTaO3). Examples of such tantalates are lithium tantalate (LiTaO3), lutetium tantalate (LuTaO4), neodymium tantalate (NdTaO4) and lead scandium tantalate (PST or Pb( Scx Ta1-x) O3. Polyoxometallate In chemistry, a polyoxometalate (abbreviated POM) is a polyatomic ion, usually an anion, that consists of three or more transition metal oxyanions linked together by shared oxygen atoms to form closed 3-dimensional frameworks. The metal atoms are ...s containing tantalum provide examples of discrete tantalum oxides that exist in solution. References Oxometallates {{inorganic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Mineralogical Association
Founded in 1958, the International Mineralogical Association (IMA) is an international group of 40 national societies. The goal is to promote the science of mineralogy and to standardize the nomenclature of the 5000 plus known mineral species. The IMA is affiliated with the International Union of Geological Sciences (IUGS). The Association supports the activities of Commissions and Working Groups involved on certain aspects of mineralogical practice and facilitates interactions among mineralogists by sponsoring and organising meetings. In particular, the IMA holds its general meeting every four years. The next meeting is scheduled in 2022 in Lyon, France. Presidents The presidents of the IMA have been: * since 2021: Anhuai Lu ** Peking University *2018–2020: Patrick Cordier (born 1961) ** Université de Lille *2016–2018: Peter C. Burns ** University of Notre Dame *2014–2016: Sergey V. Krivovichev (born 1972) ** Saint Petersburg State University *2012–2014: Walter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Araxá
Araxá () is a municipality in Western Minas Gerais state, Brazil. Its estimated population by IBGE (Brazilian Institute of Geography and Statistics) in 2020 is 107,337 inhabitants and the area of the municipality is , with making up the urban perimeter. Geography The elevation of the city center is . The highest point in the municipality is Serrra da Bocaina at , and the lowest point is the Capivara river at . In 2004 the annual average temperature was . The annual rainfall was .Prefeitura de Araxá Demographics *Population in 1970: 35,676 *Population in 1980: 53,404 *Population in 1991: 65,911 *Population in 2000: 78,997 (77,743 lived in the urban area)IBG ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrochlore
Pyrochlore () is a mineral group of the niobium end member of the pyrochlore supergroup. The general formula, (where A and B are metals), represent a family of phases isostructural to the mineral pyrochlore. Pyrochlores are an important class of materials in diverse technological applications such as luminescence, ionic conductivity, nuclear waste immobilization, high temperature thermal barrier coatings, automobile exhaust gas control, catalysts, solid oxide fuel cell, ionic/electrical conductors etc. Occurrence The mineral is associated with the metasomatic end stages of magmatic intrusions. Pyrochlore crystals are usually well formed (euhedral), occurring usually as octahedra of a yellowish or brownish color and resinous luster. It is commonly metamict due to radiation damage from included radioactive elements. Pyrochlore occurs in pegmatites associated with nepheline syenites and other alkalic rocks. It is also found in granite pegmatites and greisens. It is characteristical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niobium
Niobium is a chemical element with chemical symbol Nb (formerly columbium, Cb) and atomic number 41. It is a light grey, crystalline, and ductile transition metal. Pure niobium has a Mohs hardness rating similar to pure titanium, and it has similar ductility to iron. Niobium oxidizes in Earth's atmosphere very slowly, hence its application in jewelry as a hypoallergenic alternative to nickel. Niobium is often found in the minerals pyrochlore and columbite, hence the former name "columbium". Its name comes from Greek mythology: Niobe, daughter of Tantalus, the namesake of tantalum. The name reflects the great similarity between the two elements in their physical and chemical properties, which makes them difficult to distinguish. English chemist Charles Hatchett reported a new element similar to tantalum in 1801 and named it columbium. In 1809, English chemist William Hyde Wollaston wrongly concluded that tantalum and columbium were identical. German chemist Heinrich Rose determin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Companhia Brasileira De Metalurgia E Mineração
Companhia Brasileira de Metalurgia e Mineração (Portuguese for ''Brazilian Metallurgy and Mining Company''), or CBMM for short, is a Brazilian company that specializes in the processing and technology of niobium, extracted from its pyrochlore mine near the city of Araxá, in the Brazilian state of Minas Gerais. CBMM is by far the world's largest producer of niobium metal and its alloys, providing over 80% of the world's supply. Like the other producers of this metal, the company does not sell raw niobium ore, only ferroniobium, other niobium alloys and oxides, and the pure metal, all produced in its facilities next to the open-pit mine. As of 2016, CBMM produces 90,000 tonnes of ferroniobium equivalent per year, which is slated to be increased to 150,000 tonnes/year. The Araxá ore deposit is large enough to supply the market demand for at least 200 years at current consumption rates. CBMM was the world's first mining and metallurgy company to be ISO 14001-certified. CBMM's ni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brasília
Brasília (; ) is the federal capital of Brazil and seat of government of the Federal District. The city is located at the top of the Brazilian highlands in the country's Central-West region. It was founded by President Juscelino Kubitschek on 21 April 1960, to serve as the new national capital. Brasília is estimated to be Brazil's third-most populous city. Among major Latin American cities, it has the highest GDP per capita. Brasília was a planned city developed by Lúcio Costa, Oscar Niemeyer and Joaquim Cardozo in 1956 in a scheme to move the capital from Rio de Janeiro to a more central location. The landscape architect was Roberto Burle Marx. The city's design divides it into numbered blocks as well as sectors for specified activities, such as the Hotel Sector, the Banking Sector, and the Embassy Sector. Brasília was inscribed as a UNESCO World Heritage Site in 1987 due to its modernist architecture and uniquely artistic urban planning. It was named "City of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
