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Topic: Columbite-tantalite

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Tantalite - Wikipedia, the free encyclopedia Tantalite is a mineral that is close to columbite. Tantalite is used as an ore of tantalum and niobium and as mineral specimens. Tantalite is black to brown in both color and streak. en.wikipedia.org /wiki/Tantalite

COLUMBITE - LoveToKnow Article on COLUMBITE It is usually found associated with tantalum, the chief minerals containing these two elements being tantalite, columbite, fergusonite and yttrotantalite; it is also a constituent of pyrochlor, euxenite and samarskite. Tantalite is from Finland, and it has recently been found in some abundance in the deposits of cassiterite in the tin-field of Greenbushes in the Blackwood district, Western Australia. Columbium compounds are usually prepared by fusing columbite with an excess of acid potassium sulphate, boiling out the fused mass with much water, and removing tin and tungsten from the residue by digestion with ammonium sulphide, any iron present being simultaneously converted into ferrous sulphide. www.1911encyclopedia.org /C/CO/COLUMBITE.htm

AFB EXPLORATION (PTY) LIMITED Tantalite is a tantalite of iron and manganese and is nearly always associated with columbite, a niobate of iron and manganese. The ratio of tantalite to columbite varies greatly in different deposits and ranges from nearly pure tantalite to nearly pure columbite. Tantalite concentrates are processed to produce tantalum metal and other tantalum products and about half of tantalum consumption is used in the manufacture of electronic capacitors. www.afb-exploration.com /DEU/AnnexureB_1.htm

Columbite,Columbite Information,Columbite Uses,Columbite Suppliers Columbite is the more niobium rich end member and tantalite is the more tantalum rich end member. Tantalite's greatest difference from columbite is its much greater specific gravity, 8.0+ compared to columbite's 5.2. Columbite is the most widespread niobium mineral and makes for an important ore of the industrially useful metal. www.mineralszone.com /minerals/columbite.html

Tantalite Columbite bearing alluvial occur over the peripheral rocks but are sparse over the granite which furnished the differentiates. The present drainage has effected the concentration of columbite in alluvial. The distribution of the later granite is of some economic significance as it's late differentiates intruded into the roof rocks furnished the columbite which has been concentrated into alluvial deposits. www.highlandminerals.com /custom2.html

Mineral description : Columbite - Tantalite If you have some questions, suggestions or comments you are welcome to write me a line or two. www.geology.neab.net /minerals/columbit.htm

Mineralogical Society of America This suggests that Nb or Ta is not strongly preferred in the columbite structure, rather that the composition of the melt controls the Nb/Ta ratio of the columbite-tantalite mineral that crystallizes from it. Tantalite is more soluble than columbite for all melt compositions that have been investigated experimentally. By contrast, in peraluminous melts manganotantalite is significantly more soluble than manganocolumbite, thus fractional crystallization leads to a trend of decreasing Nb/Ta. www.minsocam.org /MSA/Special/Pig/PIG_CQ/PIG_CQ_Kjellman.html

columbite --  Encyclopædia Britannica Tantalite is the principal ore of the metal tantalum. It is the world's largest producer of columbite, a mineral containing iron, magnesium, and niobium. Major minerals of niobium are pyrochlore [(Na, Ca)2Nb2O6F] and columbite [(Fe, Mn)(Nb, Ta)2O6], consisting of niobate, tantalate, iron, and manganese. www.britannica.com /eb/article?tocId=9024890

morabisi.html Results show columbite / tantalite occurrences with associated high rare earth, base metal, Mn, U and W concentrations are related to pegmatites in granites in an oval 10km wide area, broadly ringed by basaltic to doleritic intrusions. This project was designed to attempt to establish the source of the columbite / tantalite, better define the extent of the deposits and also explore for other elements of commercial value. Previous exploration by the Geological Survey and private companies led to the discovery of alluvial columbite / tantalite deposits in tributaries of the Morabisi River, a left bank tributary of the Mazaruni. www.sdnp.org.gy /ggmc/morabisi.html

Chemistry of columbite-tantalite minerals in rare metal granitoids, Eastern Desert, Egypt -- Abdalla et al. 62 (6): 821 -- Mineralogical Magazine The columbite-tantalite commonly exhibits a mottled or patchy zoned texture with the rims consistently higher in Ta than the cores, reflecting the later effect of a corrosive supercritical vapour phase. Columbites of the apogranites commonly exhibit progressive (either normal or reverse) zoning which can be attributed to the disequilibrium conditions (e.g. However, the Mn-enriched columbites are commonly encountered in the apical parts of the apogranites and formed in response to high mu minmag.geoscienceworld.org /cgi/content/abstract/62/6/821

Gem, Rock, and Mineral Postage Stamps Featuring Columbite-tantalite Columbite is the end-member with more niobium (at one time niobium was called columbium, hence the name columbite); tantalite is the end-member with more tantalum. Since columbite and tantalite exhibit very similar properties and since a detailed chemical analysis is generally needed to distinguish the two minerals, specimens from the series are typically referred to as "columbite-tantalite." Additional Notes: Columbite forms a series with the mineral tantalite. stampmin.home.att.net /columbite-tantalite.htm

tantalite - B2B Online Trade Show In China, Global and Taiwan ,Manufacturers , suppliers Copper concentrate, Copper cathodes, tantalite, columbite, nickel ore, cobalt ore, selenium, tellurium, iron ore, zirconium ore, Copper concentrate, Copper cathodes, tantalite, columbite, nickel ore, cobalt ore, selenium, tellurium, iron ore, zirconium ore Tantalite, columbite, tin, byrite, Tantalite, columbite, tin, byrite Tantalite, zinc, leade, columbite, Tantalite, zinc, leade, columbite www.commerce.com.tw /Manufacturers_Tantalite.html

Tantalite < Minerals < Chemistry < Science < : news feed The Australia-based miner of gold, tantalite, diamonds and other base metals said the Namibian Commissioner of the Ministry of Mines and Energy didn't give a... The partnership will focus on two areas: extending the YAG portfolio to include Er: and Yb:YAG Crystals and consolidating Lithium tantalite production. / science / chemistry / minerals / tantalite schema-root.org /science/chemistry/minerals/tantalite

Equatorial Guinea - Opportunities Oportunidades Discrete but laterally extensive (15 Km2) occurances of pegmatite, with strong indications of tantalite columbite mineralization, including average grades of 3.0 - 7.5 Kg/m3 in overlying eluvial and alluvial deposits, occur in the Acocsang area. In 1975, Soviet Union geologists completed a preliminary assessment of gold, tantalite columbite, iron ore, bauxite and radioactive minerals. Sporadic investigations prior to 1975 noted major geological divisions and highlighted potential for oil, gold, base metals, bauxite and pegmatite minerals such as tin, tungsten and tantalite-columbite. www.orgitecture.com /guinea/information1392/information_show.htm?doc_id=13947

Uganda Gold Mining Ltd (UGM on CDNX). The funds from the private placement will be used for exploration on Uganda Gold's tantalite properties in Uganda, mostly for diamond drilling, extension of an underground adit on the east old workings of the Nyanga mining location, and for administration. After a long and unexplained silence, Uganda Gold broke silence to announce in March 2002 that exploration commenced in January 2002 on their Nyanga tantalite property, including extending an old mine adit and cross-cut for 29m and that diamond drilling 150m east of the adit encountered pegmatite immediately. The property contains 2 areas of previous tantalite mine workings 330m apart. www.mine.mn /Placer_Stockfile_Uganda_Gold_Mining.htm

Coltan columbite tantalite is a black tar like... Coltan columbite tantalite is a black tar like... It is used to produce tantalum mostly for use in capacitors, which are used in a vast array of small electronic devices, especially in mobile phones, laptop computers, pagers, and the like. www.geodatabase.de /coltan

FERROCOLUMBITE-MANGANOTANTALITE TRENDS IN GRANITES AND PEGMATITES: EXPERIMENTAL AND NATURAL CONSTRAINTS This is the opposite of most natural trends, indicating that columbite-tantalite crystallization does not control the Mn/Fe ratios in highly evolved granitic melts. It has long been recognized that the chemical compositions of columbite-tantalite record fractionation trends in granites and granitic pegmatites, from more primitive ferrocolumbite to highly fractionated manganotantalite (e.g. The lower solubilities of the Mn end-members indicate that columbite crystallization should result in a decrease of the Mn/Fe ratio of the residual melt. gsa.confex.com /gsa/2004AM/finalprogram/abstract_79253.htm

Mineral Information Institute - Common Minerals Columbite-tantalite group (columbium is another name for niobium): Columbite is a natural oxide of niobium, tantalum, ferrous iron, and manganese. The sample photograph is tantalite, a source for tantalum. www.mii.org /commonminerals.html

Caffe Conventional TIMS analyses of these columbite-tantalite crystals produces scattered data and reverse discordance even after HF leaching of the grains prior to dissolution, possibly reflecting the incomplete removal of the open-system metamict segments during sample preparation. Best age estimates of columbite from pegmatites in the Superior Province are; 2670 ± 5 Ma for the Pakeagama Lake pegmatite, 2644 ± 7 Ma for the Separation Rapids group, and 2665 ± 8 Ma for the Mavis Lake group. This discordance represents an analytical artefact originating from an inappropriate correction of elemental fractionation between U and Pb during ablation and extraction that itself may take its origin in the contrasting metamictization of the dated columbite and the monazite standard used. www.gfz-potsdam.de /pb4/pg2/people/romer/ROMER-46.htm

Tantalita.doc IV - EXPORTS Brazilian exports are in the form of Columbite - Tantalite concentrates, or as Fe-Nb-Ta alloys, averaging some 146 tons over the last three years, and an annual income of US$ 1, 104 thousand, the average price for these goods being of US$ 7.56/kg. Pitinga's mine — Mineração Taboca of the Paranapanema Group, in the municipal district of Presidente Figueredo (AM) commercialized in 2000 a total of 3,717 tons of Columbite -Tantalite concentrate, with 10.0% Ta2O5. This triggered a rush to stake claims in Western Amazônia, in areas where tantalite is known to occur such as Middle and High Rio Negro (AM), and near the border of Roraima, in Rorainópolis. www.dnpm.gov.br /enportal/assets/galeriaDocumento/SumarioMineral2001en/Tantalita.doc

Columbite-tantalite a valuable black mineral combining niobite and tantalite; used in cell phones and computer chips xmlns.com /wordnet/1.6/Columbite-tantalite

Principal Metals-Niobium The element is found in niobite (or columbite), niobite-tantalite, parochlore, and euxenite. Large deposits of niobium have been found associated with carbonatites (carbon-silicate rocks), as a constituent of parochlore. Most metallurgists, leading metal societies, and all but one of the leading U.S. commercial producers, however, still refer to the metal as "columbium." www.principalmetals.com /utilities/41.htm

Seller of Tantalite and Columbite In Reply to: Re: tantalite, columbite, wolframite ores posted by Peter kelly on January 15, 2002 at 17:45:04: We have Tantalite and Columbite available at our stores. www.brama.com /business/messages/14716.html

Extracting Wealth : mechanized mining equipment tantalite carbide tools for metalworking equipment and in the production mostly from tantalite and columbite mining operations in dredges, or mechanized open pit mining. Metalline's long-term Reefton Mining N.L. Reefton is actively exploring for diamonds, tantalite and precious big for large scale mechanized mining, have been identified in TANTALITE. extractingwealth.com /equip/mechanized-mining-equipment--tantalite.htm

List of minerals - Open Encyclopedia Coltan (short for minerals of the columbite group) Chabazite (a group of closely-related minerals in the zeolite group) Jade (tough, green mineral either jadeite or nephrite amphibole) open-encyclopedia.com /List_of_minerals

tantalite - Buying Leads for tantalite - Buyers, Importers, Wholesalers, Distributors We need large quanity of Tantalite ore. The content of it is 3% min. We have presently a mine that produces 65% of tantalite and we seek serious buyers only. We would like to purchase Tantalite contained Ta2O5 and Nb2O5 on regular and long term basis,... tantalite.importer.alibaba.com

Columbite-Tantalite Series Columbite and tantalite are important sources of niobium and tantalum. The columbite-tantalite series is two minerals that contain oxygen with niobium and tantalum; columbite contains more niobium, and tantalite contains more tantalum. Large deposits of these minerals are located in western Australia, Brazil, and Norway. www.alientravelguide.com /science/chemistr/inorgani/compound/multoxid/columbit.htm

tantalite, columbite, wolframite ores Re: tantalite, columbite, wolframite ores Joe 01/30/02 ( Re: tantalite, columbite, wolframite ores Tunde Adebowale 04/24/02 ( Re: tantalite, columbite, wolframite ores Peter kelly 01/15/02 ( www.brama.com /business/messages/10399.html

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