Coltan

Coltan é a mistura de dois minerais: columbita e tantalita.[1] Da columbita, extrai-se o nióbio; da tantalita, o tântalo. Esse último é um minério de alta resistência térmica, eletromagnética e à corrosão, sendo, por isso, muito utilizado na fabricação de pequenos condensadores utilizados na maioria dos aparelhos eletrônicos portáteis (celulares, notebooks, computadores automotivos de bordo). O nióbio é semelhante ao tântalo, além de ter potencial como supercondutor. Ambos os metais foram e continuam sendo fundamentais para toda a tecnologia relacionada a equipamentos eletrônicos.

As maiores reservas de tantalita (na forma coltan, ou seja, agregada à columbita) estão na República Democrática do Congo, onde, há anos, trava-se uma guerra civil envolvendo a posse das minas, além de questões étnicas, territoriais e políticas.[2] A ONU apresenta estimativas desconcertantes, como a de que já morreram mais de 4 milhões de pessoas na disputa pelo "ouro azul", além do impressionante faturamento de mais de US$250 milhões que teve o exército de Ruanda no comércio do caro mineral, sendo que não há mineração de "coltan" nesse país vizinho do Congo.

A mineração de columbita-tantalita provoca grandes impactos no meio ambiente tropical do Congo, uma vez que não são tomadas as devidas medidas de mitigação ambiental (fato óbvio no meio de uma região em guerra) além de as minas se encontrarem próximas ou mesmo dentro de parques nacionais. A obtenção desses materiais a partir da reciclagem de componentes eletrônicos é complexa e cara. Ambos os metais são extremamente caros e raros na natureza.

No Brasil, as maiores reservas de tantalita encontram-se nos estados de Roraima, sobretudo no sul do estado, e no Amapá.

  • O coltan foi bem lembrado no seriado Terminator: The Sarah Connor Chronicles (Exterminador do Futuro: As Crônicas de Sarah Connor) como o material essencial para a construção dos exterminadores.

Referências

  1. ↑ Coltão, o veneno "smart" do Congo-Democrático. novojornal.co.ao
  2. ↑ What Is Coltan? Por Imtiyaz Delawala. ABC News, 6 de janeiro de 2006.

Read other articles:

Amsal 4

Amsal 4Kitab Amsal lengkap pada Kodeks Leningrad, dibuat tahun 1008.KitabKitab AmsalKategoriKetuvimBagian Alkitab KristenPerjanjian LamaUrutan dalamKitab Kristen20← pasal 3 pasal 5 → Amsal 4 (disingkat Ams 4) adalah bagian dari Kitab Amsal dalam Alkitab Ibrani dan Perjanjian Lama di Alkitab Kristen.[1][2] Teks Naskah sumber utama: Masoretik, Septuaginta dan Naskah Laut Mati. Pasal ini terdiri dari 28 ayat. Berisi nasihat-nasihat yang diucapkan oleh menteri Salomo b...

 

Litany of Re

Ancient Egyptian funerary text of the New Kingdom of Egypt The Litany of Re (or more fully Book of Praying to Re in the West, Praying to the United One in the West) is an important ancient Egyptian funerary text of the New Kingdom.[1] Like many funerary texts, it was written on the inside of the tomb for reference by the deceased. Unlike other funerary texts, however, it was reserved only for pharaohs or very favored nobility. It is a two-part composition that in the first part invoke...

 

Arik Air

Arik AirBerkas:Arik Air Logo.png IATA ICAO Kode panggil W3 ARA ARIK Didirikan2002Mulai beroperasi30 Oktober 2006Penghubung Bandara Internasional Kotoka Bandar Udara Internasional Murtala Muhammed Bandar Udara Internasional Nnamdi Azikiwe Armada25Tujuan27SloganWings of NigeriaPerusahaan indukOjemai Investments, NigeriaKantor pusatArik Air Aviation CenterBandar Udara Internasional Murtala MuhammedIkeja, Lagos, NigeriaTokoh utama Sir Joseph Arumemi-Ikhide (Chairman) Michael Arumemi-Ikhide (CEO) ...

Front de l'Est (Seconde Guerre mondiale)

Cet article concerne le front est-européen. Pour la guerre menée par le Japon à partir de 1941 en Extrême-Orient, voir Guerre du Pacifique. Pour les autres significations, voir Front de l'Est. Front de l’Est (1941-1945) De haut en bas et de gauche à droite : chars soviétiques dans les rues de Berlin ; un char allemand Tiger I lors de la bataille de Koursk ; troupes soviétiques lors de la bataille de Stalingrad ; bombardiers allemands Stuka ; Wilhelm Keit...

 

Charles I, Duke of Elbeuf

Marquis of Elbeuf then Duke of Elbeuf Charles I de LorraineMarquis of Elbeuf then Duke of Elbeuf Count of HarcourtCoat-of-arms of ElbeufBorn18 October 1556Joinville, FranceDied4 August 1605(1605-08-04) (aged 48)Moulins, FranceSpouseMarguerite de ChabotIssueDetailCharles II, Duke of ElbeufHenri, Count of HarcourtClaude Éléonore, Duchess of RoannaisHouseHouse of LorraineFatherRené II de LorraineMotherLouise de Rieux Charles I de Lorraine, duc d'Elbeuf (Joinville, 18 October 1556 – Mou...

 

France at the 2009 World Championships in Athletics

This article needs to be updated. Please help update this article to reflect recent events or newly available information. (January 2023) Sporting event delegationFrance at the2009 World Championships in AthleticsWA codeFRANational federationFédération Française d'AthlétismeWebsitewww.athle.comin BerlinCompetitors67Medals Gold 0 Silver 0 Bronze 1 Total 1 World Championships in Athletics appearances197619801983198719911993199519971999200120032005200720092011201320152017201920222023← ...

IIIe législature de la Cinquième République française

IIIe législature de la Cinquième République française 3 avril 1967 - 30 mai 19681 an, 1 mois et 27 jours Assemblée nationale Composition UDR (200) FGDS (121) COM (73) RI (42) PDM (41) NI (9) Vacants (1) Président Jacques Chaban-Delmas (UNR)9 décembre 1958-20 juin 1969 Élections 5 et 12 mars 1967 Sénat Président Gaston Monnerville (RAD)9 décembre 1958-3 octobre 1968 Élections Gouvernement Parti(s) UNR, UDVe, UDR - FNRI Gouvernement(s) Pompidou IV 8 avril 1967-10 jui...

 

Binding off

This article includes a list of general references, but it lacks sufficient corresponding inline citations. Please help to improve this article by introducing more precise citations. (February 2008) (Learn how and when to remove this message) In knitting, binding off, or casting off, is a family of techniques for ending a column (a wale) of stitches. Binding off is typically used to define the final (usually upper, taking the cast on edge as the lower) edge of a knitted fabric, although it ma...

 

Josef Samael

American professional wrestler (born 1974) This biography of a living person needs additional citations for verification. Please help by adding reliable sources. Contentious material about living persons that is unsourced or poorly sourced must be removed immediately from the article and its talk page, especially if potentially libelous.Find sources: Josef Samael – news · newspapers · books · scholar · JSTOR (March 2010) (Learn how and when to remove t...

2016年美國總統選舉

2016年美國總統選舉 ← 2012 2016年11月8日 2020 → 538個選舉人團席位獲勝需270票民意調查投票率55.7%[1][2] ▲ 0.8 %   获提名人 唐納·川普 希拉莉·克林頓 政党 共和黨 民主党 家鄉州 紐約州 紐約州 竞选搭档 迈克·彭斯 蒂姆·凱恩 选举人票 304[3][4][註 1] 227[5] 胜出州/省 30 + 緬-2 20 + DC 民選得票 62,984,828[6] 65,853,514[6]...

 

Son Byong-ho

South Korean actor In this Korean name, the family name is Son. Son Byong-hoSon Byong-ho in 2019Born (1962-08-25) August 25, 1962 (age 61)Andong, North Gyeongsang Province, South Korea[1]OccupationActorAgentCicada I Remember Co. LtdKorean nameHangul손병호Hanja孫炳昊Revised RomanizationSon Byeong-hoMcCune–ReischauerSon Pyŏng-ho Son Byong-ho (born August 25, 1962) is a South Korean actor.[2] Son is known for his role in action films, notably, R-Point (2004), Runnin...

 

The Lord of the Rings: The Two Towers (film)

Untuk versi bukunya, lihat Dua Menara. The Lord of the Rings: The Two TowersPoster promosiSutradaraPeter JacksonProduserPeter JacksonBarrie M. OsborneFrances WalshSkenarioFrances WalshPhilippa BoyensStephen SinclairPeter JacksonBerdasarkanDua MenaraJ. R. R. TolkienPemeranElijah WoodSean AstinViggo MortensenIan McKellenAndy SerkisLiv TylerCate BlanchettJohn Rhys-DaviesBernard HillChristopher LeeBilly BoydDominic MonaghanOrlando BloomHugo WeavingMiranda OttoDavid WenhamBrad DourifAndy SerkisSea...

Myles Brand

American academic administrator This article includes a list of general references, but it lacks sufficient corresponding inline citations. Please help to improve this article by introducing more precise citations. (September 2009) (Learn how and when to remove this message) Myles BrandBrand in 20094th President of the National Collegiate Athletic AssociationIn officeJanuary 1, 2003 – September 16, 2009Preceded byCedric DempseySucceeded byJim Isch (Interim)Mark Emmert16th P...

 

Elderly care

Care serving the needs and requirements of senior citizens An old man at a nursing home in Norway Elderly care, or simply eldercare (also known in parts of the English-speaking world as aged care), serves the needs of old adults. It encompasses assisted living, adult daycare, long-term care, nursing homes (often called residential care), hospice care, and home care. Elderly care emphasizes the social and personal requirements of senior citizens who wish to age with dignity while needing assis...

 

Frans Kaisiepo International Airport

Airport in Papua, IndonesiaFrans KaisiepoAirportBandar Udara Frans KaisiepoIATA: BIKICAO: WABBSummaryAirport typePublicOwnerPertiwi Daya SembadaOperatorPT Angkasa Pura ILocationBiak, Biak Numfor Regency, Papua, IndonesiaTime zoneWIT (UTC+09:00)Elevation AMSL46 ft / 14 mCoordinates01°11′24″S 136°06′27″E / 1.19000°S 136.10750°E / -1.19000; 136.10750Websitefranskaisiepo-airport.co.id/enMapBIKLocation in Western New GuineaShow map of Western New...

Serenade (Bruch)

This article relies largely or entirely on a single source. Relevant discussion may be found on the talk page. Please help improve this article by introducing citations to additional sources.Find sources: Serenade Bruch – news · newspapers · books · scholar · JSTOR (May 2016) Max Bruch's Serenade in A minor, Op. 75 is a composition for violin and orchestra that was composed in Cologne in 1899.[1] Structure The work has four movements and t...

 

Konvensi Perserikatan Bangsa-Bangsa tentang Hukum Laut

Konvensi Perserikatan Bangsa-Bangsa tentang Hukum Laut Nama panjang: United Nations Convention on the Law of the Sea (UNCLOS) Ditandatangani10 Desember 1982LokasiMontego Bay, JamaikaEfektif16 November 1994[1]Syarat60 negara telah meratifikasiPihak160[2]   Telah meratifikasi   Telah ditandatangani akan tetapi belum diratifikasi  Tidak menandatangani Konvensi Perserikatan Bangsa-Bangsa tentang Hukum Laut (bahasa Inggris: United Nations Conventio...

 

Kedar "Bud" Pyatt

American mathematician This biography of a living person needs additional citations for verification. Please help by adding reliable sources. Contentious material about living persons that is unsourced or poorly sourced must be removed immediately from the article and its talk page, especially if potentially libelous.Find sources: Kedar Bud Pyatt – news · newspapers · books · scholar · JSTOR (July 2015) (Learn how and when to remove this message) Kedar...

الحسنية الدرامي

هذه المقالة يتيمة إذ تصل إليها مقالات أخرى قليلة جدًا. فضلًا، ساعد بإضافة وصلة إليها في مقالات متعلقة بها. (مارس 2020) الحسنية الدرامي معلومات شخصية الميلاد 10 ديسمبر 1956 (68 سنة)  الجنسية المغرب  الحياة العملية المهنة منافسة ألعاب القوى  الرياضة ألعاب القوى  تعديل مصدر...

 

八王子市立長房中学校

八王子市立長房中学校 2023年4月 北緯35度39分28秒 東経139度17分19秒 / 北緯35.6578度 東経139.28857度 / 35.6578; 139.28857座標: 北緯35度39分28秒 東経139度17分19秒 / 北緯35.6578度 東経139.28857度 / 35.6578; 139.28857過去の名称 八王子市立長房中学校国公私立の別 公立学校設置者 八王子市校訓 強く 正しく 美しく設立年月日 1974年4月1日共学・別学 男女共学�...