JOAO COUTINHO FERREIRA

JOAO COUTINHO FERREIRA

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Synthesis of dibenzo-15-crown-5 - DMSO resin – silica used for isotopic separation of the lithium
2024 - FERREIRA, J.C.; BERGAMASCHI, V.S.; OTOMO, J.I.; SOUZA, R.F. de; SANTOS, D.G.; MORAES, T.S.; VEGA, J.B.
The development of new materials and ligands based on crown ethers capable of mono- and binuclear coordination compounds, free or linked to silica matrices, has been studied by several authors for the isotopic separation of lithium 6/lithium 7. The present work shows the synthesis of dibenzo-15-crown-5 in high-purity silica gel polymeric material, pore size 60 Å, 70–230 mesh. B15C5 was dissolved in a mixture of 15 g of phenol in 250 mL of methanol and 100 mL of DMSO in a reaction vessel, and approximately 50 g of porous silica granules were added to the solution, which was stirred for approximately 10 minutes by a rotoevaporator shaker under reduced pressure at room temperature. After the evaporation of methanol, approximately 10 g of formalin, 70 mL of formic acid, and 1 mL of sulfuric acid were added to the reaction flask and left to form the polymerization for 24 h under reduced pressure at 70?C. The pressure decreased further near the boiling point of the reactant solution by removing the reactant solution. The silica resins with a yellowish color were washed with water repeatedly until the neutral pH of the washing water was reached. The characterization of the dry resin spheres under reduced pressure was carried out via thermogravimetric analysis, infrared and ultraviolet spectroscopy, and nuclear magnetic resonance to verify the presence of carbon and hydrogen. The prepared material was placed in a chromatographic column positioned in series, forming stages, in the form of a cascade, for isotopic separation of the 99.98% purity lithium solution. Isotopic separation using the prepared material was evaluated by a quadrupole mass spectrometer.
Purification of lithium ions from lithium hydroxide solution by ion exchange method using cationic resin AG 50W-X8 e HPR 1200
2024 - FERREIRA, JOAO C.; SANTOS, DANIELA da C.G.; OTOMO, JULIANA I.; BERGAMASCHI, VANDERLEI S.; BUSTILLOS, JOSE O.V.
Separation techniques of lithium isotopes by ion exchange method and monitoring by ICP-MS
2024 - BUSTILLOS, J.O.V.; OTOMO, J.I.; LEAO, P.H.B.; ROVELO, B.S.; SANTOS, D.C.G.; FERREIRA, J.C.; BERGAMASCHI, V.; ALVARENGA, V.
Comparison of ion exchange methods for lithium-7 isotopic enrichment for application in PWR reactors
2024 - OTOMO, JULIANA I.; SANTOS, DANIELA da C.G.; COUTINHO, JOAO F.; BERGAMASCHI, VANDERLEI S.; BUSTILLOS, JOSE O.W.V.
Calcium determination by permanganometry and EDTA complexation
2024 - SANTOS, DANIELA da C.G.; NASCIMENTO, LETICIA da S.; BUSTILLOS, JOSE O.W.V.; COUTINHO, JOAO F.; BERGAMASCHI, VANDERLEI S.; OTOMO, JULIANA I.
Optimizations on Lithium ion exchange separation and isotopic measurements
2022 - OTOMO, JULIANA I.; GIMENEZ, MAISE P.; ANDRADE, MARIANA N. de; MONTEIRO, LUCILENA R.; NASCIMENTO, LETICIA da S.; BATAGLIA, HENRIQUE; LEAO, PAULO H.B.; CECILIO, PRISCILA de S.; BERGAMASCHI, VANDERLEI; COUTINHO, JOAO F.; BUSTILLOS, JOSE O.W.V.
Introduction: The Lithium-7 is of interest for nuclear application, being used for primary cooling of PWR (Pressurized Water Reactor) reactors [1]. An environmentally friendly technique is required to replace the Mercury amalgam technique used worldwide [1,2]. This work aims to present the preliminary results of the development of 7Li separation by ion exchange. Methods: A 120 mm x1.0 cm i.d. glass column filled with Dowex 50W-x16 resin was used. A total of 3.0 liters of 0.2 M CH3COOLi solution percolated the column in order to saturate and displace the formed band of 6Li and 7Li. Fractions were collected every 50 mL, then the resin was washed with 5M HNO3 and ultrapure water. The fractions were filtered and evaporated at 80°C, finally taken up with HNO3 1%. Samples were analyzed by ICP-OES – SPECTRO ARCOS. The fractions were analyzed by ICP-MS, model ELAN 6000 – SCIEX. For isotopic ratio measurement, with the parameters of gas flow of approximately 1.1 L min-1, RF 600 W, gas flow rate 1.2 L min-1, Peak Hopping mode, dwell time 80 and 480 for 6Li and 7Li (respectively), 50 sweeps per reading, 1 read per replicate and 10 replicates. Results: A total of 63 samples were collected from the separation experiment. The Li isotopic ratio measured for each fraction was assessed by ANOVA one-way considering the differences among fractions. A statistical significant difference was observed between the fraction 1 and the remainder fractions and the load solution. The remaining fractions showed an isotopic ratio around the natural abundance (6Li/7Li: 7.59%/92.41% = 0.082). The isotopic ratio of this sample indicated enrichment of 7Li of 0.92% in the fraction number 30. Conclusions: The method of ion exchange with Dowex 50W-x16 resin was efficient on 7Li separation and through ICP-MS method was able to measure the δ 84%₀ enrichment of the 7Li. The isotopic separation procedure via ion exchange is still being studied, however the results are promising.
Sodium interference in lithium isotope ratio analysis by Inductively Coupled Plasma Mass Spectrometry
2022 - ANDRADE, MARIANA N. de; OTOMO, JULIANA I.; GIMENEZ, MAISE P.; NASCIMENTO, LETICIA da S.; NASCIMENTO, HENRIQUE B. do; LEAO, PAULO H.B.; CECILIO, PRISCILA de S.; FERREIRA, JOAO C.; BERGAMASCHI, VANDERLEI S.; BUSTILLOS, OSCAR V.
Introduction: Naturally occurring lithium consists of two stable isotopes, 6Li (7.591%) and 7Li (92.409%) and have applications in nuclear technology, pharmaceutical, automotive and geological research. Enriched 7Li isotope in LiOH form has been used as a pH regulator for Pressurized Water Reactor (PWR) reducing corrosion in the primary water circuit [1-3]. The determination of lithium isotopic composition was analyzed by Inductively Coupled Plasma Mass Spectrometry after ion exchange processes, which has been considered a promising technique for the separation of Li isotopes. One of the concerns in ICP-MS analysis is sodium interference. The presence of sodium in the lithium-containing sample has potential implications for the accuracy of isotopic ratio measurements. For this reason, a method is described for the study of sodium interference in 7Li 295,88%₀ and 303,30%₀ enriched solutions. Methods: For this study, the reference standard L-SVEC was used, it has an isotopic abundance of 92.409% for 7Li and 7.591% for 6Li (6Li/7Li ratio = 0.08251) and solutions enriched at 295,88%₀ (6Li/7Li ratio = 0.06661) and 303,30%₀ (6Li/7Li ratio = 0.06810) of 7Li. Concentrations of 50 μg L-1 of lithium were maintained for the solutions used and it was evaluated with the addition of 50, 100, 300, 450 and 1000 μg L-1 of sodium on the enriched samples suffered significant changes in their isotopic ratio. The ICP-MS used for the sample analysis was a PerkinElmer SCIEX Elan 6000. For the isotopic ratio measurement the parameters used was nebulizer gas flow of approximately 0.94 L min-1 , Radio Frequency (RF) 600 W, gas flow rate 1.2 L min-1 , Peak Hopping mode, dwell time 80 and 480 ms for 6Li and 7Li respectively, 50 sweeps per reading, 1 read per replicate and 10 replicates. Results: For this study, 24 samples were analyzed being divided into four sets of samples with 6 samples each set. The sets were composed of samples without addition of sodium and samples with addition of 50, 100, 300, 450 and 1000 μg L-1 of sodium. The first set of samples, composed of the 295,88%₀ enriched sample, had a standard deviation of 3.59✕10-4. The second set of samples, composed of the 303,30%₀ enriched sample, had a standard deviation of 2.63✕10-4. The third and fourth set of samples, composed of aliquots of the L-SVEC standard, obtained a standard deviation of 2.22✕10-4 e 2.54✕10-4, respectively. Showing that the addition of sodium did not significantly interfere in the ratio of lithium isotopes 6 and 7 according to standard deviation. Conclusions: Through the results obtained from the experiment, it was observed that the variation in the ratio between isotopes 6 and 7 of lithium was not significant for the results of analysis in ICP-MS. However, it should be noted that for the purposes of lithium isotope separation processes using ion exchange resins, the interference of sodium in the chromatographic separation needs to be evaluated.
Purification of lithium hydroxide by ion-exchange processes for application in nuclear reactors
2021 - GIMENEZ, MAISE P.; OTOMO, JULIANA I.; FERREIRA, JOAO C.; BERGAMASCHI, VANDERLEI; BUSTILLOS, OSCAR V.
Fractionation lithium isotopes by inorganic ion exchange
2021 - FERREIRA, JOAO C.; SENEDA, JOSE A.; BERGAMASCHI, VANDERLEI S.; GIMENEZ, MAISE P.; BUSTILLOS, OSCAR V.
Thorium and lithium in Brazil
2019 - OLIVEIRA, GLAUCIA A.C. de; LAINETTI, PAULO E.O.; BUSTILLOS, JOSE O.W.V.; PIRANI, DEBORA A.; BERGAMASCHI, VANDERLEI S.; FERREIRA, JOAO C.; SENEDA, JOSE A.
Brazil has one of the largest reserves of thorium in the world, including rare earth minerals. It has developed a great program in the field of nuclear technology for decades, including facilities to produced oxides to microspheres and thorium nitrates. Nowadays, with the current climate change, it is necessary to reduce greenhouse gas emissions, one of this way is exploring the advent of IV Generation reactors, molten salt reactors, that using Thorium and Lithium. Thorium's technology is promising and has been awaiting the return of one nuclear policy that incorporates its relevance to the necessary levels, since countries like the BRICS (without Brazil) have been doing so for years. Brazil has also been developing studies on the purification of lithium, and this one associated to thorium, are the raw material of the molten salt reactors. This paper presents a summary of the thorium and lithium technology that the country already has, and its perspectives to the future.