Les oxynitrures dopés terre rare présentent des propriétés intéressantes pour un usage en tant que luminophore pour LEDs blanches. Une nouvelle famille de luminophores dopés Eu2+ ou Ce3+ avec un réseau hôte oxynitrure de structure apatite a été étudiée : La8+xSr2-x(Si/Ge)6NyO26+x/2-3/2y. L'ammonolyse d'un précurseur oxyde de structure apatite a été utilisée comme technique générale de nitruration. Elle a permis de diminuer substantiellement la température de nitruration en comparaison avec la méthode classique par réaction à l'état solide sous atmosphère mixte N2/H2. Les différentes luminescences des luminophores obtenus ont été étudiées et corrélées à la structure cristalline à l'aide de différentes techniques de caractérisation.La structure apatite présente notamment la particularité de proposer plusieurs sites anioniques pour l'introduction de l'azote ainsi que deux sites cationiques pour les ions terre rare activateurs. L'utilisation de nombreuses techniques de caractérisation (IR, Raman, RMN, diffraction des neutrons) a permis d'obtenir des informations sur la position de l'azote. En parallèle, la comparaison des propriétés optiques avec celles de composés réduits sous Ar/H2 a permis d'attribuer les émissions aux différents sites cristallins disponibles dans la structure. Des mesures de rendement quantique ainsi que des tentatives d'optimisation des propriétés de luminescence ont été effectuées.

The glass-ceramics containing apatite [Ca10(PO4)6(O,F2)] and wollastonite [CaO&amp / #8226 / SiO2] crystals as the predominant crystalline phases, (A-W glass-ceramics) were produced through controlled crystallization of the glasses in the MgO-CaO-SiO2-P2O5-F system. Phases formed in the crystallized counterpart of the glasses were identified by powder X-ray diffraction (XRD) analysis. The crystal morphology of the resultant glass-ceramics was examined using a scanning electron microscope (SEM). The crystallization kinetic parameters consisting of the activation energy for crystallization, (E), the Avrami parameter, (n), and frequency factor of the glass were determined with regard to small amount of TiO2 additions using non-isothermal differential thermal analysis (DTA). The values for E and n for apatite and wollastonite were 460 kJ/mol and 433 kJ/mol, and 3.1&plusmn / 0.1 and 1.5&plusmn / 0.1, respectively. When 4 wt% TiO2 was incorporated into the base glass, the values for E decreased to 408 and 320 kJ/mol for apatite and wollastonite, respectively / but the values for n increased from 3.1&plusmn / 0.1 to 3.3&plusmn / 0.1, and from 1.5&plusmn / 0.1 to 1.9&plusmn / 0.1 for apatite and wollastonite, respectively. TiO2 is an effective nucleating agent in this glass system for promoting the precipitation of both apatite and wollastonite crystals. Structure oriented changes in the indentation microhardness and tribological properties of the A-W glass-ceramics were evidenced. The microhardness at the free surface was 650&plusmn / 12 HV, but decreased with increasing depth distance from the free surface and attained 520&plusmn / 8 HV at a distance 0.5 mm below the free surface. The wear rate at the free surface was 0.7&plusmn / 0.05 &times / 10-4 mm3/Nm, but increased as the distance from the free surface increased and became 2.9&plusmn / 0.15 &times / 10-4 mm3/Nm at a distance 0.5 mm below the free surface. Tribological properties of the A-W glass-ceramics were compared with those of commercially available dental ceramics including IPS Empress 2&reg / , Cergo Pressable Ceramic&reg / , Cerco Ceram&reg / , Super porcelain EX-3&reg / , and bovine enamel. The wear rate, friction coefficient, and wear mechanisms of the A-W glass-ceramics were similar to currently used artificial dental materials.

Three studies on Cordilleran foreland basin deposits in the western U.S.A. constitute this dissertation. These studies differ in scale, time and discipline. The first two studies include basin analysis, flexural modeling and detailed stratigraphic analysis of Upper Cretaceous depocenters and strata in the western U.S.A. The third study consists of detrital zircon U-Pb analysis (DZ U-Pb) and thermochronology, both zircon (U-Th)/He and apatite fission track (AFT), of Upper Jurassic to Upper Cretaceous foreland-basin conglomerates and sandstones. Five electronic supplementary files are a part of this dissertation and are available online; these include 3 raw data files (Appendix_A_raw_isopach_data.txt, Appendix_C_DZ_Data.xls, Appendix_C_UPb_apatite.xls), 1 oversized stratigraphic cross section (Appendix_B_figure_5.pdf), and 1 figure containing apatite U-Pb concordia plots (Appendix_C_Concordia.pdf). Appendix A. Subsidence in the retroarc foreland of the North American Cordillera in the western U.S.A. has been the focus of a great deal of research, and its transition from a flexural foreland basin, during the Late Jurassic and Early Cretaceous, to a dynamically subsided basin during the Late Cretaceous has been well documented. However, the exact timing of the flexural to dynamic transition is not well constrained, and the mechanism has been consistently debated. In order to address the timing, I produced new isopach maps from ~130 well log data points that cover much of Utah, Colorado, Wyoming and northern New Mexico, producing in the process, the most detailed isopach maps of the area. These isopach maps span the Turonian to mid-Campanian during the Late Cretaceous (~93–76 Ma). In conjunction with the isopach maps I flexurally modeled the Cordilleran foreland basin to identify when flexure can no longer account for the basin geometry and identified the flexural to dynamic transition to have occurred at 81 Ma. In addition, the dynamic subsidence at 81 Ma is compared to the position of the hypothesized Shatsky Oceanic Plateau and other proposed drivers of dynamic subsidence. I concluded that dynamic subsidence is likely caused by convection over the plunging nose of the Shatsky Oceanic Plateau. Appendix B. The second study is a detailed stratigraphic study of the Upper Cretaceous, (Campanian, ~76 Ma) Sego Sandstone Member of the Mesaverde Group in northwestern Colorado, an area where little research has been done on this formation. Its equivalent in the Book Cliffs area in eastern Utah has been rigorously documented and its distal progradation has been contrastingly interpreted as a result of active tectonism and shortening in the Cordilleran orogenic belt ~250 km to the west and to tectonic quiescence, flexural rebound in the thrust belt and reworking of proximal coarse grained deposits. I documented ~17 km of along depositional dip outcrops of the Sego Sandstone Member north of Rangely, Colorado. This documentation includes measured sections, paleocurrent analysis, a stratigraphic cross section, block diagrams outlining the evolution of environments of deposition through time, and paleogeographic maps correlating northwest Colorado with the Book Cliffs, Utah. The sequence stratigraphy of the Sego Sandstone Member in northwest Colorado is similar to that documented in the Book Cliffs area to the south-southwest, sharing three sequence boundaries. However, flood-tidal delta assemblages between fluvio-deltaic deposits that are present north of Rangely, Colorado are absent from the Book Cliffs area. These flood-tidal-delta assemblages are likely caused by a large scale avulsion event in the Rangely area that did not occur or was not preserved in the Book Cliffs area. In regards to tectonic models that explain distal progradation of the 76 Ma Sego Sandstone Member to be caused by tectonic quiescence and flexural rebound in the thrust belt, the first study shows that at 76 Ma, flexural processes were no longer dominant in the Cordilleran foreland, so it is inappropriate to apply models driven by flexure to the Sego Sandstone Member. Dynamic processes dominated the western U.S.A. during the Campanian, and flexural processes were subordinate. Appendix C. In order to test the tectonic vs. anti-tectonic basin-filling models for distal coarse foreland deposits mentioned above, the third study involves estimating lag times of Upper Jurassic to Upper Cretaceous conglomerates and sandstones in the Cordilleran foreland basin. Measuring lag time requires a good understanding of both the stratigraphic age of a deposit and the thermal history of sedimentary basin. To further constrain depositional age, I present twenty-two new detrital zircon U-Pb (DZ U-Pb) sample analyses, spanning Upper Jurassic to Upper Cretaceous stratigraphy in Utah, Colorado, Wyoming and South Dakota. Source exhumation ages can be measured using thermochronology. To identify a thermochronometer that measures source exhumation in the North America Cordillera, both zircon (U-Th)/He, on eleven samples, and apatite fission track (AFT) thermochronology, on eleven samples was performed. Typically, the youngest cooling age population in detrital thermochronologic analyses is considered to be a source exhumation signal; however, whether or not these apatites are exhumed apatites or derived from young magmatic and volcanic sources has been debated. To test this, I double dated the detrital AFT samples, targeting apatites with a young cooling age, using U-Pb thermochronology. Key findings are that the maximum depositional ages using DZ U-Pb match existing biostratigraphic and geochronologic age controls on basin stratigraphy. AFT is an effective thermochronometer for Lower to Upper Cretaceous foreland stratigraphy and indicates that source material was exhumed from >4–5 km depth in the Cordilleran orogenic belt between 118 and 66 Ma, and zircon (U-Th)/He suggests that it was exhumed from <8–9 km depth. Double dating apatites (with AFT and U-Pb) indicate that volcanic contamination is a significant issue; without having UPb dating of the same apatite grains, one cannot exclude the possibility that the youngest detrital AFT population is contaminated with significant amounts of volcanogenic apatite and does not represent source exhumation. AFT lag-times are 0 to 5 Myr with relatively steady-state to slightly increasing exhumation rates. We compare our data to orogenic wedge dynamics and subsidence histories; all data shows active shortening and rapid exhumation throughout the Cretaceous. Our lag-time measurements indicate exhumation rates of ~.9–>>1 km/Myr.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Irreplaceable element for life, phosphorus is the main component of apatite, a mineral present in phosphate rock. The increasing in agriculture productivity would not be possible without the use of fertilizers. However, being a non-renewable resource, the phosphorus is susceptible to depletion. The exploitation of economically mineable deposits of phosphate ore leads to large losses of phosphorus in the stage of processing. In contrast, the demand for fertilizers in the country only increases. Currently, more than half of world production of phosphate concentrate is produced by flotation. The column flotation has been adequate to the processing of complex and low grades ores, that is the case of Brazilian deposits, and also fine size ranges. However, difficulty in concentrating ores of igneous origin may be aggravated in the presence of dissolved ions in process water used in flotation, since the recirculated water increases the ionic concentration. According to the literature, the process of concentration of apatite is strongly affected by the presence of ionic species, since they interact with the surface of apatite particles by changing the efficiency of the flotation process. Thus, the aim of this work was to evaluate the influence of water contaminated with ions F-, Ca2 +, Mg2 + and PO43- provides in the performance of apatite flotation or, in other words, in recovery, P2O5 content and selectivity of the process, to the coarse and fine ores carried out in a flotation column. And through central composite design (CCD), the influence of these ions in the apatite recovery and P2O5 content for low and high concentrations of contaminants. The results showed that the individual effect of each ion studied provided a substantial decrease in recovery, with different sensitivity to the size ranges studied. The most expressive decreases in apatite recovery are related to contaminants calcium and phosphate, where the first had a maximum reduction in the recovery of 58 and 51% for the coarse and fine, respectively, since the calcium consume the collector, reducing the amount available for the apatite collection. Phosphate confirms its strong depressant effect on the apatite particles, since for the coarse particles, there was a reduction in maximum recovery of 55% and 59% for the fines. For the contaminant magnesium, it is clear the critical effect on the process selectivity, related to the gangue minerals Fe2O3 and SiO2, since P2O5 content, in the presence of this ion, suffered a considerable decrease (up to 8 percentage points), independent of particle size. Magnesium, that also react with the collector, was responsible for the sharp increase in the consumption of NaOH, used to adjust the pulp pH, reaching up to 4 times higher compared to the standard test. The influence of fluoride ion represented an increase in the ratio of selectivity P2O5/SiO2, especially for the fine material, indicating a possible depressing effect on the silicate gangue. For the CCD, carried out at low contaminants concentrations, it is clear the interactions between calcium and magnesium with phosphate, contributing to the increase in the recovery, and between magnesium and fluoride, which contributed to the increase in the P2O5 content. This behavior is probably due to the fact that these ions form insoluble compounds among them, removing these ionic species from the system. As for the CCD performed to high contaminants concentrations, all the flotation tests resulted in very low values of recovery and grade. This fact may be associated with the formation of colloidal precipitates in large quantities, leading to indiscriminate coating of the mineral particles present, including apatite, preventing the reagents action. / Elemento insubstituível para a vida, o fósforo constitui o principal componente da apatita, mineral presente na rocha fosfática. O crescente aumento da produtividade na agricultura não seria possível sem o uso dos fertilizantes. Entretanto, por ser um recurso não-renovável, o fósforo está suscetível ao esgotamento. A exploração dos depósitos economicamente lavráveis de minério fosfático leva a grandes perdas de fósforo na etapa de beneficiamento. Contrariamente, a demanda por fertilizantes no país só aumenta. Atualmente, mais da metade da produção mundial de concentrado fosfático é produzido por flotação. A coluna de flotação tem se mostrado adequada ao beneficiamento de minérios complexos e de baixos teores, caso das reservas brasileiras, e também de granulometria mais fina. No entanto, a dificuldade em concentrar minérios de origem ígnea pode ser agravada quando em presença de íons dissolvidos na água de processo empregada na flotação, uma vez que a água recirculada aumenta a concentração iônica presente. De acordo com a literatura, o processo de concentração da apatita é fortemente afetado pela presença de espécies iônicas, uma vez que estas interagem com a superfície da partícula de apatita alterando a eficiência do processo de flotação. Sendo assim, este trabalho teve por objetivo avaliar a influência que a água contaminada com os íons F-, Ca2+, Mg2+ e PO43- acarreta no desempenho da flotação em coluna de apatita, ou seja, na recuperação, teor de P2O5 e seletividade do processo, para minério de granulometria grossa e fina, e, por meio de planejamento do tipo composto central (PCC), a influência destes mesmos íons na recuperação e teor de P2O5 para baixas e altas concentrações de contaminantes. Os resultados obtidos permitem concluir que o efeito individual de cada íon estudado proporcionou uma substancial queda na recuperação, apresentando diferente sensibilidade em relação à faixa granulométrica empregada. Os resultados mais expressivos de queda na recuperação são referentes aos contaminantes cálcio e fosfato, onde o primeiro teve uma redução máxima na recuperação de 58 e 51% para o material grosso e fino, respectivamente, em virtude do cálcio consumir o coletor, reduzindo a quantidade disponível para a coleta de apatita. O fosfato confirma seu forte efeito depressor sobre as partículas de apatita, visto que, para os grossos, houve uma redução máxima na recuperação de 55% e de 59% para os finos. Para o contaminante magnésio, fica claro o efeito crítico na seletividade do processo, em relação aos minerais de ganga Fe2O3 e SiO2, uma vez que o teor de P2O5, quando em presença deste íon, sofreu uma considerável queda (até 8 pontos percentuais), independente do tamanho de partícula. O magnésio, além de reagir também com o coletor, foi responsável pelo aumento acentuado no consumo de NaOH, utilizado para regular o pH da polpa, chegando a ser 4 vezes maior, comparado ao teste branco. A influência do íon fluoreto representou um aumento na razão de seletividade P2O5/SiO2, principalmente para o material fino, indicando possível efeito depressor sobre a ganga silicatada. Para o PCC realizado a baixas concentrações de contaminantes, fica evidenciado as interações entre os cátions cálcio e magnésio com fosfato, contribuindo para o aumento da resposta recuperação, e entre magnésio e fluoreto, onde colaborou para o aumento da resposta teor. Este comportamento, provavelmente, é devido ao fato destes íons formarem compostos insolúveis entre si, sequestrando estas espécies iônicas do sistema. Já para o PCC realizado a altas concentrações de contaminantes, todos os ensaios de flotação resultaram em valores extremamente baixos de recuperação e teor. Este fato pode estar associado à formação de precipitados coloidais em grande quantidade, levando a recobrir indiscriminadamente as partículas minerais presentes, inclusive a apatita, impedindo a ação dos reagentes. / Mestre em Engenharia Química

Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2017-12-14T17:27:41Z No. of bitstreams: 2 Dissertação - Izabela Letícia Almeida de Moraes - 2017.pdf: 2791313 bytes, checksum: 95bb215d71f301f1f487b1e919c6304c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-12-18T13:41:37Z (GMT) No. of bitstreams: 2 Dissertação - Izabela Letícia Almeida de Moraes - 2017.pdf: 2791313 bytes, checksum: 95bb215d71f301f1f487b1e919c6304c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-12-18T13:41:37Z (GMT). No. of bitstreams: 2 Dissertação - Izabela Letícia Almeida de Moraes - 2017.pdf: 2791313 bytes, checksum: 95bb215d71f301f1f487b1e919c6304c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-06-01 / Brazilian soils present acidity and in some parts are deficient in nutrients such as Nitrogen (N), Phosphorus (P) and Potassium (K). For the soil to be arable it is indispensable the artificial fertilization. Brazil is known worldwide for being a major producer of grains, according to the National Company of Supply (CONAB), assuming the position of the second largest soybean producer in the world in the harvest years 2015/2016. Apatite is the main natural source of phosphorus recognized as a raw material for the manufacture of fertilizers. The origin of the phosphate rock in Brazil is predominantly igneous, presenting a mineralogy containing silicate and carbonate mineral particles. Due to these gangue minerals present in the phosphate rock the flotation process becomes indispensable during the processing, to separate the apatite from the contaminants and to obtain the minimum level of impurities so that the fertilizers are produced to the required specifications. The difficult separation of the silica-carbonate ores from apatite occurs in the similarity of surface chemistry. The collecting reagent is used in the flotation process to aid in the separation of barley ores, in which the fatty acids, among them the saponified fatty acids, are those traditionally used, and the fatty acids obtained from vegetable or animal oil are matter Collector master prime. Jatropha curcas L., known as jatropha (Jatropha curcas L.), has been arousing national interest in recent years because it is a species with excellent oil quality. The cultivation of this oleaginous species occurs in several Brazilian regions, is a perennial plant and resistant to several variations of soil and climate. Jatropha stands out for the production capacity of its oil, which reaches 50% of its seeds, and for the lipid composition rich in fatty acids; Its major acids are linoleic, oleic, and palmitic. This study aims to evaluate the selectivity of the jatropha oil used as collector in the apatite, calcite and quartz flotation. And to be used as a collector the jatropha oil was characterized and tested in two methods of saponification, and the plant species was saponified at a temperature of approximately 90 oC so that in the other method the oil was saponified at room temperature. The mineral samples were chemically analyzed by X-ray fluorescence, scanning electron microscope (SEM) images, X-ray dispersive energy (EDS) spectrometry and potential zeta measurements. The test conditions were obtained using the concentrations of 1.0; 2.5; 5.0; 7.5; 10.0 mg / L in pH's 8, 9 and 10. In order to evaluate the performance of saponified jatropha oil, tests were carried out under the same conditions with the industrial collector FLOTIGAM 5806 from Clariant. The results show that cold saponified jatropha oil (PMSF) was better than hot saponified jatropha oil (PMSQ) and, when compared to the Flotigam, the results showed a similar performance. The PMSF and PMSQ collectors showed selectivity for apatite and calcite and for quartz collectors did not achieve significant recovery of the mineral. Thus, it can be concluded that jatropha oil as a collector has a potential for apatite flotation. / Os solos brasileiros apresentam acidez e em algumas partes são deficientes em nutrientes, como Nitrogênio (N), Fósforo (P) e Potássio (K). Para o solo se tornar mais fértil é indispensável a adubação artificial. O Brasil é mundialmente conhecido por ser um grande produtor de grãos, de acordo com a Companhia Nacional de Abastecimento (CONAB), assumindo o lugar de segundo maior produtor de soja do mundo na safra anos 2015/2016. A apatita é a principal fonte natural de fósforo reconhecido como matéria prima para a fabricação de fertilizantes. A origem da rocha fosfática no Brasil é predominantemente ígnea apresentando uma mineralogia contendo partículas minerais de silicato e carbonato. Devido a esses minerais de ganga presentes na rocha fosfática o processo de flotação se torna indispensável durante o beneficiamento, para separar a apatita dos contaminantes e obter o nível mínimo de impurezas para que os fertilizantes sejam produzidos seguindo as especificações exigidas. A difícil separação dos minérios sílico-carbonatado da apatita se dá à semelhança da química da superfície. O reagente coletor é usado no processo de flotação para auxiliar na separação dos minérios de ganga, em que os ácidos graxos, dentre eles os ácidos graxos saponificados, são os tradicionalmente utilizados, sendo que os ácidos graxos obtidos de óleo vegetal ou animal são a matéria prima principal do coletor. O pinhão manso, vem despertando interesse nacional nos últimos anos por ser uma espécie que apresenta um óleo de excelente qualidade. O cultivo dessa espécie oleaginosa ocorre em várias regiões brasileiras, é uma planta perene e resistente a diversas variações de solo e clima. O pinhão manso se destaca pela capacidade de produção do seu óleo, que chega a 50% de suas sementes, e pela composição lipídica rica em ácidos graxos; seus ácidos majoritários são linoleico, oleico e palmítico. Este estudo tem como objetivo avaliar a seletividade do óleo de pinhão manso utilizado como coletor na flotação apatita, calcita e quartzo. E para ser utilizado como coletor o óleo de pinhão manso foi caracterizado e testado em dois métodos de saponificação, sendo que a espécie vegetal foi saponificada em uma temperatura de aproximadamente 90 oC de modo que no outro método o óleo foi saponificado em temperatura ambiente. As amostras minerais foram analisadas quimicamente por fluorescência de raios-X (FRX), imagens de microscópio eletrônico de varredura (MEV), espectrometria de energia dispersiva de raios-X (EDS), difração de raios-X (DRX) e medidas potencial zeta (PZ). As condições dos testes foram obtidas utilizando as concentrações de 1,0; 2,5; 5,0; 7,5; 10,0 mg/L em pH’s 8, 9 e 10. Com o objetivo de avaliar a performance do óleo de pinhão manso saponificado foram realizados testes nas mesmas condições com o coletor industrial FLOTIGAM 5806 da empresa Clariant. Os resultados mostram que os coletores do óleo de pinhão manso saponificado a frio (PMSF) apresentaram melhor performance que o óleo de pinhão manso saponificado a quente (PMSQ) e, quando comparados com o Flotigam, os resultados mostraram uma performance semelhante. Os coletores PMSF e PMSQ mostraram que existe seletividade para a apatita e calcita e para o quartzo os coletores não alcançaram recuperação significativa do mineral. Desse modo, conclui-se que o óleo de pinhão manso como coletor apresenta um potencial para a flotação de apatita.

Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2016-10-25T18:03:57Z No. of bitstreams: 2 Dissertação - Canuele Adamiane Tiago Pachêco - 2016.pdf: 5425547 bytes, checksum: 0db655cc600b41b3158eda2fce20cd1a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2016-10-27T17:28:23Z (GMT) No. of bitstreams: 2 Dissertação - Canuele Adamiane Tiago Pachêco - 2016.pdf: 5425547 bytes, checksum: 0db655cc600b41b3158eda2fce20cd1a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-10-27T17:28:23Z (GMT). No. of bitstreams: 2 Dissertação - Canuele Adamiane Tiago Pachêco - 2016.pdf: 5425547 bytes, checksum: 0db655cc600b41b3158eda2fce20cd1a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-09-13 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The aim of this work was to evaluate the potential of macaúba’s pulp oil as anionic collector in flotation of apatite, comparing with industrial sinks (FLOMIN C9012 and FLOTIGAM 5806). Macaúba’s pulp oil was submitted to chemical characterization, with the determination of the levels of acidity and saponification, in addition to infrared analysis. The minerals were submitted to chemical characterization by x-ray fluorescence (FRX) mineralogical, by x-ray diffraction (DRX) and scanning electron microscope (MEV) with energy dispersive spectrometry (EDS). Zeta potential measurements were made also of minerals in solution of electrolyte indifferent (NaCl). The collectors were previously subjected to saponification by two methods, one hot and one cold. Microflotação tests were done in modified Hallimond tube with the use of pure minerals of apatite, calcite and quartz, varying the pH and the concentrations of the collecting solutions. Assessed the saponification method, times of conditioning and flotation, the recovery from the collectors, the selectivity between the minerals and the influence of pH. It was observed that the methodology of saponification by cold method proved to be more suitable. 7 min conditioning and flotation 1 min were more favorable times. Only macaúba’s pulp oil hit the recovery of 90 % established for the smallest reagent concentrations, in the three pHs. The reagents FLOMIN C9012 and FLOTIGAM 5806, reached the desired recovery using higher dosages to pick up. The apparent selectivity OPMSF introduced between the mineral apatite, calcite and quartz for the three pHs tested, and concentrations of 1.0 and 2.5 mg/L. Gave a consumption of about 842 g/t, concentrated to OPMSF and FLOMIN C9012 and 2105 g/t of concentrate to 5806 FLOTIGAM. The results of microflotação in Hallimond modified tube indicated that macaúba’s pulp oil can act satisfactorily in the flotation of apatite. The economic analysis showed that in addition to gains against the cost of industrial collectors the OPMSF has advantages over the volume of consumption to FLOTIGAM 5806. / O objetivo deste trabalho foi avaliar o potencial de aplicação de óleo da polpa da macaúba como coletor aniônico na flotação de apatita, comparando com coletores industriais (FLOMIN C9012 e FLOTIGAM 5806). O óleo da polpa da macaúba foi submetido à caracterização química, com a determinação dos índices de acidez e saponificação, além de análise por infravermelho. Os minerais foram submetidos à caracterização química por fluorescência de raios-X (FRX), mineralógica por difração de raios-X (DRX) e imagens de microscópio eletrônico de varredura (MEV) com espectrometria de energia dispersiva de raios-X (EDS). Também foram realizadas medidas potencial zeta dos minerais em solução de eletrólito indiferente (NaCl). Os coletores foram previamente submetidos à hidrólise alcalina por duas métodos, um a frio e outro a quente. Testes de microflotação foram feitos em tubo de Hallimond modificado com o uso dos minerais puros de apatita, calcita e quartzo, variando o pH e as concentrações das soluções coletoras. Avaliou-se o método de saponificação, os tempos de condicionamento e flotação, a recuperação obtida com os coletores, a seletividade entre os minerais e a influência do pH. Observou-se que a metodologia de saponificação pelo método a frio mostrou-se mais adequada. O condicionamento de 7min e 1min de flotação foram os tempos mais favoráveis. Somente o óleo da polpa de macaúba saponificados a frio atingiu a recuperação estabelecida de 90 % para as menores concentrações do reagente, nos pHs 8, 9 e 10. Os reagentes FLOMIN C9012 e FLOTIGAM 5806, atingiram a recuperação desejada utilizando dosagens superiores ao coletor pesquisado. O OPMSF apresentou seletividade aparente entre os minerais de apatita, calcita e quartzo para os três pH’s testados e, em concentrações de 1,0 e 2,5 mg/L. Obteve-se um consumo de aproximadamente 842 g/t de concentrado para OPMSF e FLOMIN C9012 e 2.105 g/t de concentrado para o FLOTIGAM 5806. Os resultados de microflotação em tubo de Hallimond modificado indicaram que o óleo da polpa da macaúba pode atuar satisfatoriamente na flotação de apatita. A análise econômica mostrou que além dos ganhos relação ao custo dos coletores industriais o OPMSF possui vantagens sobre o volume de consumo para o FLOTIGAM 5806.

Hydroxyapatite (HAP) coatings are used in orthopaedic surgery for bone regeneration. Current methods of phase quantification of HAP coatings suffer from drawbacks. A novel methodology of quantitative phase analysis of HAP coatings has been devised and validated. This method, based on whole pattern fitting with a fundamental parameters approach, incorporates amorphous calcium phosphate (ACP) and apatite phases into structural refinements. A comparison of the structural and chemical properties of plasma sprayed (PS) and novel electrodeposited (ED) HAP coatings has been conducted. ED coatings contained less ACP and more preferred orientation than the PS coatings, although the stoichiometry was similar. In vitro investigations of PS and ED coatings in simulated body fluid and foetal calf serum revealed that both are bioactive. A carbonated apatite layer produced on the ED coatings was -0.7μm thick with a stoichiometry and chemical constituents similar to that of natural bone apatite. PS coatings produced a nanocrystalline carbonated apatite layer (-4μm). For the first time it has been possible to model crystalline HAP and nanocrystalline apatite as independent phases and obtain accurate lattice parameters for each. A positive linear correlation has been made between microstrain and the solubility of HAP and carbonated apatites. Dissolution studies have shown that the behaviour of HAP and carbonated apatite is dominated by crystallite size at low undersaturation and by crystallite size and microstrain at high undersaturation for crystallites between -30OA- 1000A. Metastable equilibrium occurred for crystallites <_400A at low undersaturation. Carbonate content did not affect the solubility or dissolution behaviour. A novel technology for coating polymeric tape with HAP for potential use in anterior cruciate ligament reconstruction has been devised. Mechanical tests have demonstrated that no adverse properties are induced by the coating technology. Cell culture studies have shown that the HAP layer is capable of enhanced attachment, proliferation and differentiation of osteoblast cells compared to uncoated tape.

Carbonatites are unique and enigmatic magmatic rocks of unclear origin, with very specific mineralogy and geochemical properties. They are predominantly composed of magmatic calcite or other carbonate minerals (Le Bas 1987) and have low content of SiO2 (Le Maitre 2002). Origin of these peculiar magmas is still not clear but they appear to represent an important "window" into processes in Earth's mantle. They are considered either as residual melts from a fractionated carbonated nephelinite or melilitite (Gittins 1989; Gittins and Jago 1998), as immiscible fractions of CO2-saturated silicate melts (Freestone and Hamilton 1980; Amundsen 1987; Kjarsgaard and Hamilton 1988, 1989; Brooker and Hamilton 1990; Kjarsgaard and Peterson 1991; Church and Jones 1995; Lee and Wyllie 1997; Dawson 1998; Halama et al. 2005; Brooker and Kjarsgaard 2011), or as primary melts which are were generated from CO2-bearing peridotite through partial melting (Wallace and Green 1988; Sweeney 1994; Harmer and Gittins 1998; Harmer et al. 1998; Ying et al. 2004). Abundances of rare earth elements (REE) are often high in carbonatites because carbonatitic magmas can dissolve these elements much easily than silicate magmas (Nelson et al. 1988). Carbonatitic magma can also dissolve large quantities of Sr, Ba, P and mainly Zr and Nb,...

Titanium alloys are widely used for manufacturing of bone implants. Recent studies proved superior mechanical and chemical properties of TiNb alloys. The performance of TiNb is analyzed on Ti39Nb alloy and on evaporated layers of Ti, Nb and TiNb. Performance is compared to Ti6Al4V and pure Ti. This work is focused on the early stage of a bone growth process (studied in vitro). An investigation of this early stage has not been found in any available literature. At this early stage, CaHPO4 compound is formed. This compound is accompa- nied by Mg oxide formation. It is a difference to later stage of this process (as observed in many studies) where the layer is created solely by hydroxylapatite, Ca10(PO4)6(OH)2. The thermal oxidation of surface leads to a grain structure and to a rougher surface. The surface with different roughness effects growth rate depending on material. Generally, the best performance is achieved with TiNb (only polished as well as subsequently thermally oxidized), followed by Ti. 1

Rapid technological advancements and growing environmental consciousness created a shifting dynamic of metal demand within the context of contemporary global challenges. The metals play a pivotal role in this transformation and remarkable surge in demand is expected. Mining districts such as the Kiruna area in northern Sweden, provide access to raw materials, assuring supply chain security, sustainability, and an environmentally friendly future. The district is part of the northern Norrbotten ore province, Sweden and is known for hosting the Kiruna-type iron oxide-apatite (IOA) deposits with associated magnetite-hematite-REE ores such as the Per Geijer deposits, and a range of other deposits, including the Viscaria Cu-(Fe-Zn), Pahtohavare Cu-Au and the Rakkurijärvi iron oxide-copper-gold (IOCG) deposits.  As the discoveries of significant near-surface deposits are declining, mining companies face a pivotal choice between pursuing resource extraction from lower-grade reserves or to focus on deeper exploration targets. The geological understanding of the subsurface decreases with increasing depth, and the reliance on geophysical techniques becomes more important in reducing the search space. Using geophysics to locate and understand elements of a mineral system requires a good understanding of the physical and chemical properties of the rocks that can be translated into geological implications. Mineral system knowledge and geological concepts can be translated into geological models that can be further used in geophysical inversions with the aim of improving targeting by iterative modeling. A geophysical inversion is in fact a realization of a physical property model, therefore the value added by the geophysical model is dependent of how well the relationship between the geology and its petrophysical signature is understood. The petrophysical characterization of geological environments offers the possibility to improve the understanding of geophysical responses, serving as a link in iterative geological-geophysical modeling.  The approach presented in the current study includes the building of three-dimensional lithological and structural framework models, and investigating the petrophysical footprint in connection with lithology, alteration, and rock fabric from the Kiruna mining district. Geological modeling and petrophysical characterization are important components within the comprehensive mineral system modeling framework and enhance geophysical investigations aimed at detecting and assessing iron oxide mineral systems. A rule-based hybrid implicit-explicit geological modeling technique proved to be useful in the integration of surface and subsurface data of the Kiruna mining district, and a structural framework and geological model was produced that provides insights into the relationship between lithological units and structures. Drill core observations indicate a competency contrast between lithological units confirming previous surface-based observations. Deposit scale structural analysis in connection with the geological models indicated the proximity of NW-SE to SW-NE trending brittle conjugate fault networks with iron-oxide apatite ore lenses, revealing juxtaposition of individual ore lenses. Complementing structural analysis and geological modeling, petrophysical characterization in connection with lithogeochemical, mineralogical, and textural investigations revealed that density and p-wave seismic velocity can be used as a general lithological indicator, while magnetic susceptibility is influenced by secondary processes. Heterogeneous strain accommodation by lithological units indicates a strong influence on density, seismic properties, and the ferromagnetic properties of the samples. Metasomatic processes alter the intrinsic properties of the samples by increasing or decreasing the physical properties of the rocks from the Kiruna area, by controlling the feldspar, mica, magnetite, and ferromagnesian mineral content. Nevertheless, an extensive sample population must be investigated to understand the large-scale effects. The present work serves as a foundation for quantitatively integrated exploration models that use geological models and petrophysical characterization as calibration tools to model mineral systems.