F.M.S. CARVALHO
14 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 14
Artigo IPEN-doc 12517 Hydrogen production by steam reforming over Cu and Ni catalysts supported on ZrO2 and Al2O3 microspheres2007 - BERGAMASCHI, V.S.; CARVALHO, F.M.S.Artigo IPEN-doc 10700 Resolucao do sistema residuario U (VI)-etanol-piridina2005 - FERREIRA, J.C.; LAINETTI, P.E.O.; CARVALHO, F.M.S.; ABRAO, A.Artigo IPEN-doc 18463 Influência de MgO e SiOsub(2) nas características de cerâmicas à base de Alsub(2)TiOsub(5)2012 - GUEDES SILVA, C.C.; CARVALHO, F.M.S.; ZANINELLI, G.; GENOVA, L.A.Artigo IPEN-doc 10778 Estudo do tratamento de um residuo de torio e terras raras por cromatografia de extracao2005 - ZINI, J.; ABRAO, A.; CARVALHO, F.M.S.; FREITAS, A.A.; SCAPIN, M.A.Artigo IPEN-doc 19434 Separation of rare earth by column chromatography using organic resins XAD/DEPHA2013 - ZINI, J.; FERREIRA, J.C.; BERGAMASCHI, V.S.; SANTOS, I.; CARVALHO, F.M.S.Artigo IPEN-doc 08841 Transformacao via peroxido de um hidroxido bruto de torio em nitrato para camisas de lampiao2002 - FREITAS, A.A.; CARVALHO, F.M.S.; FERREIRA, J.C.; ABRAO, A.Artigo IPEN-doc 08679 Uso de um misturador-decantador na purificacao de torio proveniente do hidroxido de torio bruto2002 - GOMES, L.F.; CARVALHO, F.M.S.; MINDRISZ, A.C.; SCAPIN, M.A.; SALVADOR, V.L.R.; LAINETTI, P.E.O.Artigo IPEN-doc 14337 Modeling and design of a bio-ethanol steam reforming unit2009 - CASSIANO, D.A.; PENACHIO, P.V.L.; CARVALHO, F.M.S.; CASTRO, A.J.A.Artigo IPEN-doc 08292 Recovery of uranium from the filtrate of 'ammonium diuranate' prepared from uranium hexafluoride2000 - SENEDA, J.A.; FIGUEIREDO, F.F.; ABRAO, A.; CARVALHO, F.M.S.; FRAJNDLICH, E.U.C.Artigo IPEN-doc 08294 Preparation of highly pure thorium nitrate via thorium sulfate and thorium peroxide2000 - ABRAO, A.; FREITAS, A.A.; CARVALHO, F.M.S.A simple alternative and selective method has been proposed for the preparation of thorium nitrate using as raw material a hydrated crystalline technical grade thorium sulfate. This salt was produced industrially [1] from the alkaline chemical processing of monazite sand in S. Paulo. From a crude thorium hydroxide as the raw material containing uranium and rare earth elements was prepared a technical grade thorium sulfate [Th(SO ) .9H O]. A typical analysis of this salt had shown the following composition: ThO 47–53%, R O (rare 42 2 2 23 earth oxides) 0.5–0.9%, and UO 0.01% and minor amounts of iron, titanium, phosphorus, and silicon oxides. The thorium sulfate is 3 dissolved into water and the thorium peroxide is precipitated from acidic medium by addition of hydrogen peroxide. The thorium peroxide is filtered, washed and finally dissolved with nitric acid. Samples of the thorium peroxide were dried and fired to ThO and aliquot of the 2 thorium nitrate solution was evaporated to dryness and calcined to obtain the ThO . Both ThO have high purity (.99.5%). The content 2 2 of total rare earth elements is very low (0.23% as oxide). Uranium was not detected. The great majority of the RE is precipitated and recovered from the filtrate by oxalic acid.