F.M.S. CARVALHO
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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 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 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 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.Artigo IPEN-doc 06248 Recovery of molybdenum using alumina microspheres and precipitation with selective organic reagents1998 - CARVALHO, F.M.S.; ABRAO, A.Artigo IPEN-doc 06184 Sorption and desorption of molybdenum in alumina microspheres1997 - CARVALHO, F.M.S.; ABRAO, A.Artigo IPEN-doc 09147