CARLOS ALBERTO DA SILVA QUEIROZ

CARLOS ALBERTO DA SILVA QUEIROZ

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Preparation of neodymium acetate for use in nuclear area and nanotechnology
2017 - QUEIROZ, C.A.S.; PEDREIRA FILHO, W.R.; SENEDA, J.A.
Neodymium and its compounds are being increasingly applied in the manufacture of new materials. In nuclear area neodymium isotopes are used in a variety of scientific applications. Nd-142 has been used to produce short-lived Tm and Yb isotopes. Nd-146 has been suggested to produce Pm-147 and Nd-150 has been used to study double beta decay. Due to the several modern applications using nanomaterials, more and more highly rare earth compounds have been demanded. The researches at IPEN uses the experience gained in rare earth separation for the preparation of some pure acetates, purity > 99.9% for application in nanotechnology research. A simple and economical chemical process to obtaining neodymium acetate of high purity is studied. The raw material in the form of mixed rare earths carbonate comes from Brazilian monazite. It is used the technique of strong cationic exchange resin, proper to water treatment, to the neodymium's fractionation and it is achieved a purity of 99.9% in Nd2O3 and yield greater than or equal 80%, with the elution of rare earths by EDTA solution in pH controlled. The complex of EDTA-neodymium is transformed in neodymium oxide, subsequently the oxide is dissolved in acetic acid to obtain the neodymium acetate. The solid salt was characterized via molecular absorption spectrophotometry, mass spectrometry, thermal analysis, chemical analysis and X ray diffraction. In summary the analytical data collected allowed to conclude that the stoichiometric formula for the neodymium acetate prepared is Nd(CH 3COOH)3.1.5H2O.
Conditions for the ion exchange separation of gadolinium and samarium from a mixed rare earths carbomates
1985 - QUEIROZ, CARLOS A. da S.; ABRAO, ALCIDIO
Preparacao de nitrato de cerio de alta pureza
1995 - AVILA, D.M.; QUEIROZ, C.A.S.; MUCCILLO, E.N.S.
Sintese e caracterizacao de Lnsub(2)Osub(3) (Ln=Ce e Gd) de alta pureza
1999 - AVILA, D.M.; MUCCILLO, E.N.S.; QUEIROZ, C.A.S.
Obtencao de padrao de Lasub(2)Osub(3)
1991 - QUEIROZ, C.A.S.; ABRAO, A.
Obtaining pure praseodymium acetate to use in researches and development
2010 - QUEIROZ, CARLOS A. da S.; ROCHA, SORAYA M.R. da; PEDREIRA, WALTER R.; SENEDA, JOSE A.; LOBO, RAQUEL M.; S. FILHO, WALTER
This paper presents a simple and economical procedure to obtain high purity praseodymium acetate. The raw material in the form of mixed rare earths carbonate comes from a industrial separation of rare earths, thorium and uranium in the brasilian monazite. It is used the tecnique of strong cation exchange resin, proper to water treatment, to the praseodymium's fractionation and it is achieved a purity of 99.9% in Pr6O11 and yield greater than or equal 60%, with the elution of rare earths by EDTA solution in pH controlled. The complex of EDTA-praseodymium is transformed in praseodymium oxide, subsequently the oxide is dissolved in acetic acid to obtain the praseodymium acetate. The molecular absorption spectrophotometry tecnique is used to monitoring the praseodymium content during the process and mass spectrometry to certification the purity of the praseodymium acetate. The typical praseodymium acetate obtained presents the followings contaminants in micrograms per gram: Sc(18.20±0.22); Y (20.20 ± 0.20); La (6.75 ± 0.81); Ce (26.10 ± 0.70); Nd (3.31 ± 0.63); Sm (18.30 ± 0.80); Eu (17.00 ± 0.90); Gd (19.40 ± 0.40); Tb (16.30 ± 0.50); Dy (16.90 ± 0.50), Ho(17.90 ± 0.10); Er (18.40 ± 0.70); Tm (16.90 ± 0.10); Yb (17.60 ± 0.60); Lu (17.70 ± 0.50). The high purity praseodymium acetate comes being applied, replacing the imported product, in research and development area on rare earth catalysts.
Advanced mass spectrometric applied to determinated of composition in lead (Pb-208) from residues of thorium facilities
2007 - SENEDA, JOSE A.; QUEIROZ, CARLOS A. da S.; RIZZO, SORAYA M. da R.; DIAS, MAURO S.; KAKAZU, MAURICIO H.; ABRAO, ALCIDIO
Obtencao experimental de acetato de praseodimio de alta pureza a partir de carbonatos mistos de terras raras
2010 - QUEIROZ, C.A. da S.; ROCHA, S.M.R. da; PEDREIRA, W.R.; SENEDA, J.A.; LOBO, R.M.; FILHO, W.S.
Sintese e caracterizacao de precursores a base de lantanio para aplicacao em catalisadores
2002 - ROCHA, S.M.R.; QUEIROZ, C.A.S.; ABRAO, A.
Synthesis and characterization of lanthanum acetate for application as a catalyst
2001 - ROCHA, S.M.R.; QUEIROZ, C.A.S.; ABRAO, A.