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1
Karlina, Elin, Nina Djustiana, I. Made Joni, Renny Febrida, Camellia Panatarani, and Akhyar Dyni Zakyah. "Analisis Mikrostruktur Partikel Zirkoniakalsia-silika (ZrO 2 -CaO-SiO ) Dari Pasir Zirkon Alam Indonesia Menggunakan Metode Spray Pyrolysis." Jurnal Material Kedokteran Gigi 6, no. 1 (March 1, 2017): 23. http://dx.doi.org/10.32793/jmkg.v6i1.261.
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Indonesian Natural Sand, Zircon, is an Indonesia’s natural resource that contains zirconia, silica, titania and alumina. In Dentistry, zirconia as one of the content in natural zircon sand, have the potential to be the material for filler composites. The purpose of this research was to analyze the Zirconia-Calcium-Silicate Particle (ZrO2CaO-SiO2) synthesized from Indonesia natural sand, zircon, in microstructural way. Methods: By synthesizing ZirconiaCalcium-Silicate particle (ZrO2-CaO-SiO2) from Indonesia natural zircon sand, using spray pyrolysis method. A precursor solution that is used consists of zirconil nitrate (Zr (NO3) 2), sodium silicate (Na2SiO3), and calcium hydroxide (Ca (OH) 2). Variations in the temperature of the reactor that are used were 4000C, 4500C, and 5000C with a feed rate of 6 L / min and a piezoelectric frequency of 1.7 MHz. Result showed that the better content in zirconia-calcium-silicate is the one that was synthesized at a temperature of 4500C, based on the results of EDS, SEM and XRD. The composition that is obtained in the zirconia-calcium-silicate particle has a ratio of 1: 14: 4 with the size of 500-1000nm, and has a tetragonal crystal zirconium silicate structure and dicalcium monoclinic silicate. From this research it can be concluded that the result that was synthesized at a temperature of 4500C is adequate to use as a filler based on the characterization result of SEM and XRD.
2
Li, Bing Qiang, Yao Shu, Wen Bin Dai, and Jing Kun Yu. "Effect of Zirconia, Zirconite and Zircon Mullite Additives on the Properties of Alumina Castable." Applied Mechanics and Materials 151 (January 2012): 346–49. http://dx.doi.org/10.4028/www.scientific.net/amm.151.346.
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The effect of the zirconia, zirconite, and zircon mullite additives on the properties of alumina-spinel castable has been investigated in present work. Results showed that the density of castables calcined at 110oC with the addition of zirconia and zirconite was higher than that of zircon mullite. With the increasing amount of additives, the densities of castables added with zirconia and zirconite were increased and that added with zircon mullite had not obviously difference. The apparent porosities of castables heated at 1600oC for 1h were about twice of those calcined at 110oC. The bulk densities of castables heated at 1600oC were lower than those calcined at 110oC. All the samples were expanded and the increasing amount of additives led to higher expansion rate. Though the densities of castables heated at 1600oC were lower than those calcined at 110oC, the cold crushing strength were much higher. When the amount of zirconia was less than 4maa%, the addition of zirconia was beneficial to improve the bending strength, and the addition of 4mass% zirconia led to the 18.2% improvemnt at the strength.
3
Meor Sulaiman, Meor Yusoff, Khaironie Mohamed Takip, and Ahmad Khairulikram Zahari. "In Situ XRD Study of Zirconia Phase Transformation Produced from Chemical and Mineral Processes." Materials Science Forum 840 (January 2016): 375–80. http://dx.doi.org/10.4028/www.scientific.net/msf.840.375.
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The high temperature phase transition of zirconia produced from commercial zirconyl chloride chemical was compared with that produced from a Malaysian zircon mineral. Zirconyl chloride was produced from zircon by using the hydrothermal fusion method. Initial XRD diffractogram of these samples at room temperature show that they are of amorphous structure. High temperature XRD studies was then performed on these samples; heated up to 1500°C. The XRD diffractograms shows that the crystalline structure of tetragonal zirconia was first observed and the monoclinic zirconia becomes more visible at higher heating temperature.
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Subuki, Istikamah. "Influence on Ratio of NaOH/ZrSiO4 in Alkali Fusion for Amang Zircon Sand." ASM Science Journal 17 (November 25, 2022): 1–10. http://dx.doi.org/10.32802/asmscj.2022.1093.
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Amang Zircon Sand from Amang Onn Sdn. Bhd. mineral company has a high composition of zirconium at 61.63 wt% and low silicon composition at 4.90 wt%. The high composition of zirconium in Amang zircon sand indicates the possibility to synthesise it into a zirconia. Zirconium was synthesised using alkali fusion method with different ratio of NaOH/ZrSiO4 to determine the optimum ratio based on the zirconium yield. Alkali fusion method is coupled with thermal treatment as it will produce a higher yield of zirconium with lower impurities. Then it will be leached with deionised water and hydrochloric acid (HCl). The synthesised zirconium was characterised through X-Ray fluorescence (XRF) spectroscopy, X-Ray diffraction (XRD) and particle size distribution (PSD) analysis. The XRF analysis after the fusion and thermal treatment shows a high composition of zirconium as well as great reduction of silicon. 1.2NaOH/ZrSiO4 is determined to be the optimum ratio as it has the lowest silicon impurity of 2.11 wt% and high yield of zirconium at 71.40 wt%. The low impurities will reduce the chance of cracking and maximising the efficiency of zirconia. It is supported by XRD patterns that are dominated by high zirconium peaks. The zirconium oxychloride obtained after acid leaching has a high zirconium composition. This shows that it is possible to use Amang zircon sand as a precursor to synthesis a zirconia using alkali fusion method with sodium hydroxide.
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Djustiana, Nina, Renny Febrida, Camellia Panatarani, Yuliafanny Imarundha, Elin Karlina, and I. Made Joni. "Microstructure Analysis of Zirconia-Alumina-Silica Particles Made from Indonesia Natural Sand Synthesized Using Spray Pyrolysis Method." Key Engineering Materials 720 (November 2016): 285–89. http://dx.doi.org/10.4028/www.scientific.net/kem.720.285.
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Zircon sand is one of Indonesian natural resource that is potential to be used as composite filler. Natural zircon sand can be found in several places in Indonesia, i.e. Riau Islands, Bangka-Belitung, and the Borneo. Zircon sand contains zirconia compound; while ZrO2 is the oxide crystal of zirconia compound. The mechanical and esthetical supremacy of zirconia is the reason why the usage of zirconia as nanocomposite filler mixed with alumina and silica increases. Spray pyrolysis method was used to synthesized natural zircon sand of Indonesia with temperature variety of 400°C, 500°C and 600°C. Spray pyrolysis decomposed zircon sand into powder in nano-sized. Microstructure analysis conducted were SEM, EDS, and XRD. SEM analysis showed that the morphology of particle was spherical, uniform, and regular with size of 100-500nm. EDS and XRD showed best results at the temperature of 400°C. Analysis result of EDS indicated that the largest atomic percentage was owned by sodium with ratio of Zr:Al:Si of 1:2:54 at temperature of 400°C. The XRD pattern of 400°C revealed that the crystal structure of zirconium silicate (ZrSiO4) was tetragonal, the structure of quartz (SiO2) was trigonal, and the structure of corundum aluminum oxide (Al2O3) was rhombohedral. Synthesis of zirconia-alumina-silica particles from natural zircon sand of Indonesia could be used as composite filler based on the characterization results.
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Ngọc. "NGHIÊN CỨU BIẾN TÍNH BỀ MẶT HẠT NANO ZIRCONI OXIT BẰNG POLYDIMETYL SILOXAN." Journal of Military Science and Technology, no. 72 (April 12, 2021): 66–72. http://dx.doi.org/10.54939/1859-1043.j.mst.72.2021.66-72.
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Nano zirconi oxit (ZrO2) được sử dụng rộng rãi trong nhiều ngành công nghiệp để cải thiện tính chất cơ lý cũng như khả năng chịu nhiệt của vật liệu nền. Tuy nhiên, các hạt nano ZrO2 thường có xu hướng kết tụ với nhau nên dẫn đến hiệu quả sử dụng nano ZrO2 không được như mong muốn. Bài báo này trình bày kết quả nghiên biến tính nano ZrO2 bằng polydimetyl siloxan (PDMS). Nghiên cứu đã đưa ra được các điều kiện phản ứng tối ưu là tỷ lệ về khối lượng giữa bột nano ZrO2/PDMS: 1/0,5 và nhiệt độ phản ứng là 200 oC. Các kết quả phân tích phổ hồng ngoại FT-IR, phân tích phổ tán xạ năng lượng tia X, phân tích cấu trúc hình thái TEM đã chỉ ra các hạt nano ZrO2 sau quá trình biến tính bề mặt đã ghép được các nhóm siloxan lên trên bề mặt. Hạt nano ZrO2 biến tính có khả năng phân tán tốt hơn trong dung môi xylen so với hạt nano ZrO2 chưa biến tính. Do đó, các hạt hạt nano ZrO2 biến tính có thể sử dụng tốt trong công nghiệp chế tạo sơn và keo dán.
7
Stankovic, Jovan, Slobodan Milonjic, and Slavica Zec. "The influence of chemical and thermal treatment on the point of zero charge of hydrous zirconium oxide." Journal of the Serbian Chemical Society 78, no. 7 (2013): 987–95. http://dx.doi.org/10.2298/jsc121010149s.
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Two zirconia samples were prepared by precipitation from aqueous zirconium oxychloride and zirconil sulphate solutions with potassium hydroxide. The prepared zirconia samples were amorphous. The pHpzc values of zirconia samples, determined from NaCl and NaNO3 solutions, were 6.6 ? 0.1 and 6.9 ? 0.1, respectively. After prolonged hydration of zirconia in doubly distilled water, pHpzc decreased to 4.7 ? 0.3. Crystallization into tetragonal (metastable) + monoclinic zirconia appeared at 691 K. Above 873 K, tetragonal metastable phase changes to monoclinic one. It was shown that crystallite sizes of zirconia treated at 673 - 1273 K increased from 9.5 nm to 40.5 nm, respectively. The increase in temperature from 385 K to 1070 K increased the pHpzc of zirconia samples from 6.6 to 9.0, respectively.
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Valéro, Rémi, Bernard Durand, Jean-Louis Guth, and Thierry Chopin. "Influence des ions fluorure et de la silice amorphe sur la solubilité des gels de zircone et caractérisation des fluoro-complexes de zirconium en milieu moyennement acide." Canadian Journal of Chemistry 77, no. 12 (December 5, 1999): 2099–104. http://dx.doi.org/10.1139/v99-204.
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The solubility of zirconia gels versus pH is studied in order to state first the influence of F- ions alone, then the influence of the simultaneous presence of F- and amorphous silica. Two concentrations of F- ions are chosen, 0.094 and 0.314 mol L-1, corresponding to initial molar ratios F/Zr = 0.6 and 2.0. Metal fluorocomplexes formed at pH 0.5 and 2.5 are characterized by 19F NMR. The influence of F- on the solubility of zircon is also studied. It is shown that the formation of silicon complexes rich in fluorine shifts the equilibriums between the zirconium fluorocomplexes toward the complexes poor in fluorine and that, in the presence of F-, the crystallization of zircon by hydrothermal synthesis can be forecasted, for pH values in the range 0-10.Key words: zirconia gels, silica, zircon, fluoride ions, solubility, 19F NMR.
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Lin, Cui Hua, Xiong Fei Zhang, Yang Hou, Ya Li Wang, and Gui Wang. "Synthesis of Calcium Oxide Stabilized Cubic Zirconia Powders by Electrochemical Method." Advanced Materials Research 233-235 (May 2011): 2403–8. http://dx.doi.org/10.4028/www.scientific.net/amr.233-235.2403.
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Calcium oxide stabilized cubic zirconia powders were synthesized with electrochemical method using analytical reagent zirconium oxychloride and calcium oxide as the raw materials. From XRD analysis, zirconia powders doped calcium oxide are mainly being as cubic phase under the temperature lower than 1100°C. While the zirconia powders which did not doped calcium oxide were transformed from cubic phase to monoclinic phase when the powders were sintered at 750°C. The calcium oxide used as dopant in zirconia has two advantages, the first is that it can stabilize the cubic zircnnia, the second is that it can restrain the zirconia powders’ growing up.
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Damonte, Laura C., Patricia C. Rivas, Alberto F. Pasquevich, Fernanda Andreola, Federica Bondioli, Anna M. Ferrari, Laura Tositti, and Giorgia Cinelli. "Structural Characterization of Natural and Processed Zircons with X-Rays and Nuclear Techniques." Advances in Condensed Matter Physics 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/9707604.
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In ceramic industry, zircon sand is widely used in different applications because zirconia plays a role as common opacifying constituent. In particular, it is used as a basic component of glazes applied to ceramic tiles and sanitary ware as well as an opacifier in unglazed bulk porcelain stoneware. Natural zircon sands are the major source of zirconium minerals for industrial applications. In this paper, long, medium, and short range studies were conducted on zirconium minerals originated from Australia, South Africa, and United States of America using conventional and less conventional techniques (i.e., X-Ray Diffraction (XRD), Positron Annihilation Lifetime Spectroscopy (PALS), and Perturbed Angular Correlations (PAC)) in order to reveal the type and the extension of the regions that constitute the metamict state of zircon sands and the modifications therein produced as a consequence of the industrial milling process and the thermal treatment in the production line. Additionally, HPGe gamma-ray spectroscopy confirms the occurrence of significant levels of natural radioactivity responsible for metamictization in the investigated zircon samples. Results from XRD, PALS, and PAC analysis confirm that the metamict state of zircon is a dispersion of submicron disordered domains in a crystalline matrix of zircon.
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Sharafeev, Sharif M., and Vladimir I. Vereshchagin. "PHASE FORMATION PROCESSES AT LOW-TEMPERATURE FLUORINATION OF ZIRCONIUM SILICATE." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 64, no. 4 (April 11, 2021): 67–72. http://dx.doi.org/10.6060/ivkkt.20216404.6336.
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Zirconium silicate ceramics is widely used in different fields of engineering. One of the most actual problem of zircon ceramics is the requiring of high temperatures for its sintering. Perspective method for activation of silicate materials with the aim of intensification of synthesis and sintering processes is the low-temperature fluoridation with the ammonium hydrofluoride. In accordance with that, processes occurring during the interaction of plasma dissociated zircon and natural zircon with ammonium hydrodifluoride were studied. It was established that plasma dissociated zircon actively interacts with ammonium hydrofluoride in the solid phase. Natural zircon because of its chemical inertness reacts with ammonium hydrofluoride only when latter melts. The main product of fluorinating is ammonium hexafluorosilicate. By-products are ammonium hexafluorozirconate and ammonium heptafluorozirconate. Their quantity increases with the content of ammonium hydrofluoride in mixtures. Kinetic equation of reaction between zircon and ammonium hydrofluoride is k×τ = 1-(1-α)1/n. Activation energy of plasma dissociated zircon and natural zircon fluorinating reactions are 13.9 and 32.7 kJ/mol, respectively. Order of reactions (n) are 2.0 and 1.5, respectively. Thermal treatment of fluorinated materials at 400 °C leads to ammonium hexafluorosilicate sublimation and thermal dissociation of ammonium fluorozirconates to zirconium fluoride and fluorozirconate intermediates. It was established that low-temperature fluoridation of zircon makes possible to regulate chemical composition of minerals. Materials obtained by ammonium hydrofluoride treatment of plasma dissociated and natural zircon can be potentialy used in the functional zircon and zirconia-zircon ceramics technology.
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Yamagata, Chieko, João B. Andrade, Valter Ussui, Nelson Batista de Lima, and José Octavio Armani Paschoal. "High Purity Zirconia and Silica Powders via Wet Process: Alkali Fusion of Zircon Sand." Materials Science Forum 591-593 (August 2008): 771–76. http://dx.doi.org/10.4028/www.scientific.net/msf.591-593.771.
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Zircon sand was reacted with liquid caustic soda (50% NaOH) in open vessel at 600 oC for 2h. The effect of NaOH/ZrSiO4 reactant ratio on the yield of zirconia recovery was verified. Samples of fusion products water washed were characterized by X-ray diffraction (XRD) to identify the main compounds formed. Silica powders were obtained via acid catalyzed reaction and zirconia powders were resulted from crystallization of zirconium oxychoride. Both zirconia and silica powders were analyzed by XRF (X-ray fluorescence) and BET method. Laser Quasi Elastic Light Scattering (QLS) technique was used for agglomerate size distribution determination. High purity and fine zirconia and silica powders were obtained. The specific surface area of zirconia calcined at 550 oC reached ~ 70m2g-1. Silica powder calcined at 800 oC presented a high specific surface area ~ 500 m2g-1.
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Yashima, Masatomo, Taka-aki Kato, Masato Kakihana, Mehmet Ali Gulgun, Yohtaro Matsuo, and Masahiro Yoshimura. "Crystallization of hafnia and zirconia during the pyrolysis of acetate gels." Journal of Materials Research 12, no. 10 (October 1997): 2575–83. http://dx.doi.org/10.1557/jmr.1997.0342.
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Hafnia and zirconia gels were prepared by drying hafnyl or zirconyl acetate solutions. Hafnia and zirconia gels contain both hydroxyl group and bidentate acetates which are directly bonded to the metal ions. Thermal decomposition and crystallization behavior of the gels were investigated through XRD, FT-IR, and TEM. Hafnium-containing gels crystallized directly into stable monoclinic hafnia around 500–540 °C, while zirconium-containing gels first formed metastable tetragonal zirconia around 450 °C. The dissimilar crystallization behavior of the gels into metastable, tetragonal zirconia or into stable, monoclinic hafnia can be explained through the difference in free-energy changes of the tetragonal-to-monoclinic phase transformation.
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He, Yong Wu, Rui Sheng Wang, Jing Long Bu, Jun Xing Chen, and Zhi Fa Wang. "A Study on Crystallization of Fused Silica/Zirconia Ceramic Composites." Advanced Materials Research 652-654 (January 2013): 286–89. http://dx.doi.org/10.4028/www.scientific.net/amr.652-654.286.
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Fused silica particles and zirconyl chloride were used as main raw material. Meanwhile, ammonia was used as precipitator and polyethylene glycol as dispersant. Firstly, the composite powders were prepared by wet chemical synthesis. Then, fused silica/zirconia ceramic composites containing zirconia with different contents (5%, 15%, 25%, 35% and 45%) were fabricated in reduction atmosphere at 1300°C, 1350°C and 1400°C for 1 h. The thermal expansion ratios and XRD of samples were examined. The analysis of XRD indicated that the cristobalite peaks intensity of sample with more zirconia is lower at the same sintering temperature, and the intensity of cristobalite was higher while sintered at higher temperature. Zircons were found in all samples’ XRD patterns. The results of thermal expansion ratios showed the ratios of samples with more zirconia were lower, especially at higher sintering temperature. So, existence of zirconia can inhibit crystallization of fused silica/zirconia ceramic composites effectively.
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Ene, Antoaneta, Hesham M. H. Zakaly, Amany R. Salem, Ayman A. Gouda, Khalid Althumayri, Khaled F. Alshammari, Hamdi A. Awad, et al. "A New Partially Phosphorylated Polyvinyl Phosphate-PPVP Composite: Synthesis and Its Potentiality for Zr (IV) Extraction from an Acidic Medium." Separations 9, no. 11 (November 21, 2022): 382. http://dx.doi.org/10.3390/separations9110382.
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A newly synthesized partially phosphorylated polyvinyl phosphate derivative (PPVP) was functionalized to extract Zirconium (IV) from Egyptian zircon sand. The specifications for the PPVP composite were approved effectively via different techniques, namely, FT-IR, XPS, BET, EDX, TGA, 1H-NMR, 13C-NMR, GC-MS, XRD and ICP-OES analyses, which demonstrated a satisfactory synthesis of PPVP and zircon dissolution from Egyptian zircon sand. Factors controlling parameters, such as pH values, shaking time, initial zirconium concentration, PPVP dose, nitrate ions concentration, co-ions, temperature and eluting agents, have been optimized. At 25 °C, pH 0, 20 min shaking, 0.05 mol/L zirconium ions and 0.5 mol/L nitrate ions, PPVP has an exciting preservation potential of 195 mg/g, equivalent to 390 mg/L zirconium ions. From the extraction–distribution isotherm, the practical outcomes of Langmuir’s modeling are better than the Freundlich model. With a theoretical value of 196.07 mg/g, which is more in line with the experimental results of 195 mg/g. The zirconium ions adsorption onto the PPVP composite follows the pseudo-second-order kinetics with a theoretical capacity value of 204.08 mg/g. According to thermodynamic potential, the extraction process was expected to be an exothermic, spontaneous and beneficial extraction at low temperatures. The thermodynamic parameters ΔS (−0.03 kJ/mol), ΔH (−12.22 kJ/mol) and ΔG were also considered. As the temperature grows, ∆G values increase from −2.948 kJ/mol at 298 K to −1.941 kJ/mol at 338 K. Zirconium ions may be eluted from the working loaded PPVP by 0.025M HNO3, with a 99% efficiency rate. It was found that zirconium ions revealed good separation factors towards some co-ions such as Hf4+ (28.82), Fe3+ (10.64), Ti4+ (28.82), V5+ (86.46) and U6+ (68.17). A successful alkali fusion technique with NaOH flux followed by the extraction with PPVP is used to obtain a high-purity zirconia concentrate with a zircon content of 72.77 % and a purity of 98.29%. As a result of this, the improved factors could finally be used.
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Subuki, Istikamah, Mimi Fazzlinda Mohsin, Muhammad Hussain Ismail, and Fazira Suriani Mohamed Fadzil. "Study of the Synthesis of Zirconia Powder from Zircon Sand obtained from Zircon Minerals Malaysia by Caustic Fusion Method." Indonesian Journal of Chemistry 20, no. 4 (June 10, 2020): 782. http://dx.doi.org/10.22146/ijc.43936.
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The zircon powder from Zircon Minerals Malaysia is a pure premium grade zircon sand milled 1.5 µm that contain ZrSiO4, ZrO2, HfO2, SiO2, Al2O3, TiO2, and Fe2O3. The monoclinic zirconia powders were synthesized from the zircon sand of Zircon Minerals Malaysia, by caustic fusion method at calcination temperatures between 500 °C to 800 °C. The as-synthesized zirconia was characterized through X-Ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric and differential thermal analysis (TG-DTA), and X-Ray fluorescence (XRF) techniques. The XRD results show two monoclinic phases of microcrystalline zirconia. Zirconia that was calcined at 600 °C obtained the highest value of ZrO2, which was 54.48%; followed by zirconia calcined at 700 °C, 800 °C, and 500 °C, which obtained the ZrO2 values of 53.58%, 52.41%, and 51.53%, respectively, based on the XRF analysis. As-synthesized zirconia showed monoclinic phases where the surface areas were 0.0635 m2/g, 0.135 m2/g, 0.0268 m2/g, and 0.0288 m2/g, for zirconia calcined at temperatures of 500 °C, 600 °C, 700 °C, and 800 °C, respectively. The surface structure of the powder that had been calcined at 600 C showed similarities with the commercial zirconia. The similarities of the synthesized zirconia and commercial zirconia showed that the zirconia powder could be synthesized using zircon sand by caustic fusion method, even though the content of zirconia was lower compared to that of the commercial zirconia powder.
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Pidgeon, R. T., and W. Compston. "A SHRIMP ion microprobe study of inherited and magmatic zircons from four Scottish Caledonian granites." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 83, no. 1-2 (1992): 473–83. http://dx.doi.org/10.1017/s0263593300008142.
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ABSTRACTUsing the ion microprobe SHRIMP we have analysed zircons from the Ben Vuirich, Glen Kyllachy, Inchbae and Vagastie Bridge granites from the Scottish Caledonides, in an attempt to resolve the ages of inherited zircons shown to be present in these granites by previous conventional multigrain analyses. Middle Proterozoic age components were found in inherited zircons from all four granites. Late Proterozoic (900–1,100 Ma) components have been identified in zircons from the Glen Kyllachy and Ben Vuirich granites in the Grampian Highlands. A Late Archaean age has only been detected in one zircon from the Glen Kyllachy granite. The distribution of inherited components in the granite zircon populations could reflect fundamental divisions in the age composition of granite source rocks; however, detailed assessment of this possibility must await further ion microprobe analyses on zircons from many more granites.SHRIMP isotopic and U, Th and Pb analyses were made on successive shells of zoned zircon surrounding inherited cores from the Glen Kyllachy granite to monitor chemical changes during magmatic zircon growth. Results show that zircon shells have characteristic but significantly different Th, U and Pb concentrations. Magmatic zircon from the Vagastie Bridge granite also forms as clearly defined oscillatory zoned shells around unzoned nuclei of inherited zircon. However, the distinction between magmatic and inherited zircon in zircons from the Inchbae granite is less clear. Zircons from the Ben Vuirich granite occur as euhedral, magmatic zircons, or as rounded, subhedral, inherited zircon grains. A SHRIMP age of 597 ± 11 (2σ) Ma for euhedral magmatic zircon from this granite is identical, within the uncertainty, to the conventional multigrain zircon age of 590 ± 2 (2σ) Ma reported by Rogers et al. (1989) and confirms the conclusions of those authors that sedimentation of the Dalradian sequence took place in the Precambrian.
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Chittleborough, D. J., M. S. Tejan-Kella, and R. W. Fitzpatrick. "Genesis of podzols on coastal dunes in southern Queensland. V. Chemistry and mineralogy of the non-opaque heavy mineral fraction." Soil Research 36, no. 4 (1998): 699. http://dx.doi.org/10.1071/s97041.
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Eight podzols on coastal dunes from the Cooloola chronosequence, and an associated pedon from North Stradbroke Island (Amity), were studied to establish (i) the degree of homogeneity of the parent material between and within profiles, (ii) the extent of heavy mineral weathering, and (iii) whether the parent sediments of each pedon had a common proximate source. The pedons are Quartzipsamments and Troporthods with ages ranging from Holocene to Pleistocene. On the basis of ratios zircon : rutile, zirconium : titanium, and non-magnetic : very magnetic heavy minerals in the fine sand fraction (53–125 µm), we concluded that the parent materials of the Cooloola pedons were mineralogically similar. By using zirconium in the non magnetic heavy mineral fraction as an index for zircon, it is evident that there has been considerable pedogenetic weathering of the heavy mineral fraction. There is a statistically insignificant difference in hafnium concentrations of zircons which implies that parent sediments of the soils at Cooloola and North Stradbroke Island were derived from a common immediate source.
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Poernomo, Herry, Dwi Biyantoro, and Maria Veronica Purwani. "Kajian Konsep Teknologi Pengolahan Pasir Zirkon Lokal yang Mengandung Monasit, Senotim dan Ilmenit." EKSPLORIUM 37, no. 2 (December 19, 2016): 73. http://dx.doi.org/10.17146/eksplorium.2016.37.2.3054.
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ABSTRAKKeberadaan zirkon (ZrSiO4) di alam kebanyakan berasosiasi dengan beberapa senyawa oksida berharga (SOB) seperti TiO2 dan oksida logam tanah jarang atau rare earth oxides (REO). Keterdapatan mineral alam di Indonesia yang mengandung zirkonium (Zr) dan REO tersebar di 13 wilayah mulai dari Provinsi Aceh sampai Papua Barat. Berdasarkan hal tersebut, maka tujuan penelitian adalah melakukan kajian integrasi teknologi pengolahan pasir zirkon lokal yang mengandung TiO2 dan REO. Penelitian dilakukan dengan menganalisis kandungan SOB dalam sampel pasir zirkon dari daerah Landak dan Tumbang Titi Kalimantan Barat serta Bangka menggunakan XRF. Berdasarkan kandungan SOB dalam pasir zirkon tersebut dapat diprediksi bahwa pasir zirkon dari daerah Landak dan Tumbang Titi Kalimantan Barat serta Bangka mengandung mineral zirkon (ZrSiO4), ilmenit (FeTiO3), monasit (LREE, Th)PO4, dan senotim (HREE, Y, Th)PO4. Berbasis jenis mineral tersebut diperoleh hasil kajian berupa diagram alir proses konsep teknologi konsentrat zirkon menjadi ZrO2 (zirkonia) dan ZrOCl2.8H2O (zirkonium oksiklorida) derajat industri serta zirkonia dan zirconium chemicals derajat nuklir, ilmenit menjadi TiO2, monasit menjadi Nd2O3 dan konsentrat Th(OH)4, senotim menjadi Y2O3, Gd2O3 dan konsentrat Th(OH)4 dalam satu kawasan pilot plant atau pabrik yang terintegrasi. Hasil kajian disimpulkan bahwa konsep pengolahan pasir zirkon lokal yang mengandung monasit, senotim, dan ilmenit dapat dilakukan secara terintegrasi dalam satu kawasan pabrik dengan hasil multi produk. Jika hal tersebut dapat direalisasikan di Indonesia dengan tambahan sistem pengolahan air limbah terpadu, maka selain aman bagi lingkungan juga dapat menghemat biaya produksi dan memberikan nilai tambah ekonomi bagi para pemegang izin usaha pertambangan zirkon. ABSTRACTThe existence of zircon (ZrSiO4) in the nature is mostly associated with some of the valuable oxide compounds (VOC), such as TiO2 and rare earth oxides (REO). The existence of natural minerals in Indonesia containing zirconium (Zr) and REO lies in 13 regions, ranging from Aceh to West Papua province. Based on those aforementioned aspects, the goal of this research is to conduct the study of integrated technology of local zircon sand processing containing TiO2 and REO. The study was conducted by analyzing the content of VOC in zircon sand samples from the areas of Landak and Tumbang Titi West Kalimantan and Bangka by using XRF. Based on the content of VOC in this zircon sand, it can be predicted that the zircon sand from the area of Landak and Tumbang Titi West Kalimantan and Bangka contains mineral zircon (ZrSiO4), ilmenite (FeTiO3), monazite (LREE, Th)PO4, and xenotime (HREE, Th)PO4. Based on these types of mineral, the flow chart of beneficiation technology process to increase the concentration of each mineral and the flow chart of zircon concentrate process into ZrO2(zirconia) and ZrOCl2.8H2O (zirconium oxychloride) industrial grade and zirconia and zirconium chemicals nuclear grade, ilmenite into TiO2, monazite into Nd2O3, and Th(OH)4 concentrate, xenotime into Y2O3, Gd2O3, and Th(OH)4 concentrate are obtained in one area of pilot plant or an integrated factory. The results of the study concluded that the concept of local processing of zircon sands containing monazite, xenotime, and ilmenite can be either integrated in the region with the results of multi-product plant. If it can be realized in Indonesia with the addition of an integrated waste water treatment system, then in addition to safe for the environment can also save on production costs and give economic added value for shareholders zircon mining permit
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Pidgeon, R. T., A. A. Nemchin, and S. L. Kamo. "Comparison of structures in zircons from lunar and terrestrial impactitesThis article is one of a series of papers published in this Special Issue on the theme of Geochronology in honour of Tom Krogh." Canadian Journal of Earth Sciences 48, no. 2 (February 2011): 107–16. http://dx.doi.org/10.1139/e10-037.
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There have been a number of reports of the presence of shock features, such as planar fracturing and granulation, the transformation of zircon to reidite, and the breakdown of zircon to baddeleyite in zircons associated with terrestrial impacts. It has also been proposed that the progressive development of these shock features, and the degree of disturbance of the zircon U–Pb isotopic system, could be used as a qualitative measure of the shock pressures and post-shock temperatures of the impact. Such behaviour of zircon from terrestrial impacts could be potentially useful in interpreting structures and U–Pb isotopic behaviour of shocked zircons from lunar impactites. However, careful examination of over one hundred zircon grains from samples of lunar breccias from Apollo 14 and 17 have not revealed any grains with terrestrial-like shock features, such as planar deformation features (PDFs), and we have not observed the high-pressure zircon phases reidite or the breakdown of zircon to baddeleyite in zircon grains from the breccias. Most lunar zircon grains show no evidence of a disturbance of their U–Pb systems. However, we have identified a few zircons from lunar breccias that have characteristic internal structures and accompanying Pb loss that we attribute to extreme shock. These structures differ from shock features reported for zircons associated with terrestrial impacts. Whether terrestrial-like impact features were present in the lunar zircons and have been removed during transport and heating in the impact ejecta, or whether these features never developed in the first place, has not been resolved.
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Candido, LM, LN Miotto, LMG Fais, PF Cesar, and LAP Pinelli. "Mechanical and Surface Properties of Monolithic Zirconia." Operative Dentistry 43, no. 3 (May 1, 2018): E119—E128. http://dx.doi.org/10.2341/17-019-l.
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SUMMARY Purpose: This study compared monolithic zirconia with conventional ones based on mean roughness (Ra), Vickers hardness (VHN), topography, transmittance, grain size, flexural strength (FS), Weibull modulus, and fractographic behavior. Methods and Materials: One monolithic (Prettau Zircon [PR group]) and two conventional (ICE Zirkon Transluzent [IZ group] and BloomZir [BL group]) zirconias were used. Specimens were tested using a profilometer, a microhardness tester, a scanning electron microscope, a spectrophotometer, and a Universal Testing Machine (EMIC DL 2000). Ra, VHN, grain size, and transmittance were analyzed using the Kruskal-Wallis test associated with Dunn test (α=0.05). FS was analyzed using one-way analysis of variance with the Tukey honestly significant difference test (α=0.05). Results: Means and standard deviations of roughness, after sintering (Ra, in μm) and VHN, were, respectively, 0.11 ± 0.01, 1452.16 ± 79.49, for the PR group; 0.12 ± 0.02, 1466.72 ± 91.76, for the IZ group; and 0.21 ± 0.08, 1516.06 ± 104.02, for the BL group. BL was statistically rougher (p<0.01) than PR and IZ. Hardness was statistically similar (p=0.30) for all groups. Means and standard deviations of FS (in MPa) were 846.65 ± 81.97 for the PR group, 808.88 ± 117.99 for the IZ group, and 771.81 ± 114.43 for the BL group, with no statistical difference (p>0.05). Weibull moduli were 12.47 for the PR group, 7.24 for the IZ group, and 6.31 for the BL group, with no statistical differences. The PR and BL groups had higher transmittance values and grain sizes than the IZ group (p<0.05). Although the BL group had some fractures that originated in the center of the tensile surface, fractographic analyses showed the same fracture pattern. Conclusions: All tested zirconia showed similar VHN, and the monolithic zirconia had similar roughness compared to one of the conventional zirconias. In addition, the monolithic zirconia showed similar flexural strength and Weibull modulus compared to the others even though its mean grain size was larger. The total transmittance of monolithic zirconia was higher than only one of the conventional zirconias tested.
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Cheng, Ben Jun, Xing Zhong Guo, Li Li, and Jian Ming Zheng. "Effects of Zircon Additive on the Properties of 95-Alumina Ceramic." Key Engineering Materials 280-283 (February 2007): 1013–16. http://dx.doi.org/10.4028/www.scientific.net/kem.280-283.1013.
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The mechanism of the effect that zircon additive had on the properties of 95-alumina ceramic was studied and compared with that of zirconia additive. The results show that zircon additive can decrease the sintering temperature of 95-alumina ceramic, the suitable content of zircon additive is 3% and the suitable sintering temperature is1630°C; under these conditions, the 95-alumina composite ceramic can obtain satisfactory sintering and mechanical properties. Compared with zirconia additive, besides the stress-induced-phase-transformation of ZrO2 and micro-cracks, the toughened mechanism of 95-alumina ceramic with zircon additive also includes zirconia secondary crystallization in the liquid phase.
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Zhang, Quan, Guo Feng, Feng Jiang, Jianmin Liu, Lifeng Miao, Qian Wu, Tao Wang, and Weihui Jiang. "Facile preparation of ZrO2 whiskers by LiF-KCl molten salts synthesis." Processing and Application of Ceramics 15, no. 3 (2021): 219–25. http://dx.doi.org/10.2298/pac2103219z.
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Monoclinic zirconia (ZrO2) whiskers were made via the molten salt method using zirconyl chloride octahydrate (ZrOCl2 ? 8H2O) as zirconium source, potassium chloride (KCl) as molten salt and lithium fluoride (LiF) as a mineraliser. DSC-TG, XRD, FE-SEM, Raman and TEM were performed to study the effects of heat treatment temperature, holding time and heating rate on the synthesis of zirconia whiskers. The results indicate that zirconia whiskers with diameters of 50-80 nm and aspect ratios of 10-30 can be obtained by heating the precursor at slow rate (3?C/min) to 718?C for 1 h and then at faster rate (7?C/min) to 950?C for 3 h. The whiskers have a smooth surface and grow in [001] direction. The key to the ZrO2 whiskers growth is the controlled dissolution and precipitation of the ZrO2 in a LiF-KCl molten salt solution environment.
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Primachenko, V. V., I. G. Shulyk, K. I. Kushchenko, P. O. Kushchenko, Yu O. Krakhmal, L. P. Tkachenko, and Yu Ye Mishnyova. "Study on the effect of ZrO2 and SiO2 additions type on the properties of high alumina crucibles for melting heat-resistant alloys and steels." Scientific research on refractories and technical ceramics 121 (December 30, 2021): 46–54. http://dx.doi.org/10.35857/2663-3566.121.05.
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The technology of vibrocasting high-quality refractories from granular masses of different chemical composition, size, configuration and weight of products, in particular crucibles for induction melting of heat-resistant alloys was developed and introduced by JSC “URIR named after A. S. Berezhnoy”. According to the developed technology, mullite-alumina zircon-containing crucibles contain ZrO2 ~ 8 %, zirconia-containing crucibles — ~ 17 %, alumina zircon-containing crucibles — ~ 8 %, ~ 8—10 % and ~ 25 %, have open porosity < 20 %, cold crushing strength depending on the used raw materials and firing temperature within ~ 50—230 N/mm2, thermal shock resistance> 20 thermal cycles (1300 °C — water).
The article studies the effect of ZrO2 and SiO2 additives type introduced with zircon or zirconia in combination with a silica-containing additive on the main properties of vibrocasting samples after firing at 1580 °C.
As a result of the studies the high alumina samples with 10 % ZrO2, introduced by zircon or zirconia powder, were produced, which are characterized by apparent density of 3.12 and 3.08 g/cm3, open porosity of 14.4 and 15.5 %, cold crushing strength 145 and 210 N/mm2, thermal shock resistance > 20 thermal cycles and 6 thermal cycles (1300 °C — water) respectively. That is, with practically the same chemical composition, samples with zircon have better indicators of apparent density and especially thermal shock resistance than samples with zirconia in combination with silica. The high thermal shock resistance of samples with zircon can be explained by a nature of the pores which long irregular in configuration and connected to each and, as well as microfractured structure due to the decomposition of zircon and the formation of microcrystalline monoclinic zirconia while in the structure of the samples, which included zirconia powder and silica and a mixture of joint grinding of alumina and a silica-containing additive, the pores are predominantly round isolated. Considering also that zircon is a domestic material and is cheaper than imported ZrO2, it is more expedient to use zircon for crucibles.
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Wang, Teng Yu, You Guo Xu, Zhao Hui Huang, Ming Hao Fang, Yan Gai Liu, Xiao Wen Wu, Li Yin, Bao Lin Liu, and Xiao Zhi Hu. "Influence of CeO2 Additive on the Phase Transformations of Zirconia from Zircon Ore by Carbothermal Reduction Process." Key Engineering Materials 602-603 (March 2014): 238–41. http://dx.doi.org/10.4028/www.scientific.net/kem.602-603.238.
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This paper mainly discusses the influences of heating temperatures and CeO2 additive contents on the phase transformations of zirconia from zircon ore by carbothermal reduction. The phase transformations of zirconia from zircon ore by carbothermal reduction were monitored by X-ray diffraction. The microstructure of the product was characterized by scanning electron microscopy. The results show that without adding CeO2, the optimized heating temperature of zircon carbothermal reduction was 1600 °C and the main phases of the product were m-ZrO2, ZrC and β-SiC, t-ZrO2; After adding CeO2, the main phase of the products consists of t-ZrO2, m-ZrO2, ZrC and β-SiC when the heating temperature is 1600 °C. CeO2 additive can be introduced into zirconia lattice and can cause it to form cerium stabilized zirconia. Zirconia in the product would be turned into partially stabilized zirconia with cerium addition from 5 wt% to 20 wt%. However, the form of zirconia in the product is not changed greatly with the amount of CeO2 additive increase.
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Lee, Robert G., Alain Plouffe, Travis Ferbey, Craig J. R. Hart, Pete Hollings, and Sarah A. Gleeson. "RECOGNIZING PORPHYRY COPPER POTENTIAL FROM TILL ZIRCON COMPOSITION: A CASE STUDY FROM THE HIGHLAND VALLEY PORPHYRY DISTRICT, SOUTH-CENTRAL BRITISH COLUMBIA." Economic Geology 116, no. 4 (June 1, 2021): 1035–45. http://dx.doi.org/10.5382/econgeo.4808.
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Abstract The detrital zircons in tills overlying the Guichon Creek batholith, British Columbia, Canada, have trace element concentrations and ages similar to those of zircons from the bedrock samples from which they are interpreted to have been sourced. Rocks from the core of the batholith that host porphyry copper mineralization have distinct zircon compositions relative to the distal, barren margin. We analyzed 296 zircons separated from 12 subglacial till samples to obtain U-Pb ages and trace element compositions. Laser ablation U-Pb ages of the detrital zircons overlap within error with chemical abrasion-thermal ionization mass spectrometry U-Pb ages of the Late Triassic Guichon Creek batholith and confirm that the detrital zircons are likely derived from the batholith. The youngest intrusions of the batholith produced the Highland Valley Copper porphyry deposits and contain distinctive zircons with elevated Eu/EuN* >0.4 attributed to high magmatic water contents and oxidation states, indicating higher porphyry copper potential. Zircon from till samples adjacent to and 9 km down-ice from the mineralized centers have mean Eu/EuN* >0.4, which are indicative of potential porphyry copper mineralization. Detrital zircon grains from more distal up- and down-ice locations (10–15 km) have zircon Eu/EuN* mean values of 0.26 to 0.37, reflecting background values. We conclude that detrital zircon compositions in glacial sediments transported several kilometers can be used to establish the regional potential for porphyry copper mineralization.
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Liang, Li Ping, and Cai Xia Su. "Facile Deposition of Zirconia Optical Films Based on the Solvothermal Treatment of Zirconyl Nitrate-Water-Methanol System." Applied Mechanics and Materials 217-219 (November 2012): 1033–37. http://dx.doi.org/10.4028/www.scientific.net/amm.217-219.1033.
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Zirconia optical films have been facilely deposited based on a modified sol-gel route, which involved solvothermal-treating a mixture of zirconyl nitrate, water, and methanol at 80 °C to produce zirconia-based sols, spin-coating the sols on K9 glass substrates, and then calcining the films at moderate temperatures. The experiments show that, at the proper volume ratio of methanol to water VM/VW(from 40/35 to 70/5), the high deprotonation-condensation reaction rate of the precursor zirconium salt, along with the moderate critical supersaturation level of the reaction medium, give rise to stable and uniform sols comprising particles with mean hydrodynamic diameter of 10-40 nm. This enables rapid deposition of zirconia-based films with a comparatively high refractive index of 1.62 (at 1064 nm). After calcination at 400 °C, the purification and crystallization of film material endow the film with a high refractive index of 1.91 (at 1064 nm).
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McElhinney, Tara R., Tim J. Dempster, and Peter Chung. "The influence of microscale lithological layering and fluid availability on the metamorphic development of garnet and zircon: insights into dissolution–reprecipitation processes." Mineralogical Magazine 86, no. 1 (December 13, 2021): 9–26. http://dx.doi.org/10.1180/mgm.2021.97.
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AbstractThe response of garnet and zircon to prograde amphibolite-facies metamorphism in late Proterozoic mica schists from the Scottish Highlands has been investigated. Spatial analysis of zircon populations using scanning electron microscopy was undertaken in Dalradian Schists that have undergone a sequence of prograde garnet growth and localised breakdown reactions involving coupled dissolution–reprecipitation. Fluid availability and matrix permeability strongly control this metamorphic response and different generations of garnet contain radically different populations of metamorphic micro-zircon and associated changes in the detrital zircon population. Micro-zircon abundance increases during garnet growth, whereas that of detrital zircon decreases. The mineralogy of the matrix influences zircon abundance in porphyroblast phases, where garnet overgrows a micaceous matrix zircon-rich garnet forms and where it overgrows a quartzofeldspathic matrix the result is zircon-poor garnet. Following garnet growth, micro-zircon abundance decreases at each stage of the prograde reaction history, with sillimanite-zone schists containing the lowest abundance, suggesting micro-zircons are texturally less stable at staurolite- and sillimanite-grade metamorphism. Micro-zircons are distributed evenly across host minerals in the matrix, with the exception of retrograde chlorite where micro-zircons are absent due to fluids removing Zr before new zircon can precipitate. There is an overall decrease in the mode of zircon at each stage of the reaction history, indicating that zircon is a highly reactive phase during amphibolite-facies metamorphism and is very sensitive to individual prograde and retrograde reactions.
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Coenraads, Robert R., Pongsak Vichit, and F. Lin Sutherland. "An unusual sapphire–zircon–magnetite xenolith from the Chanthaburi Gem Province, Thailand." Mineralogical Magazine 59, no. 396 (September 1995): 465–79. http://dx.doi.org/10.1180/minmag.1995.059.396.08.
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AbstractA sapphire, zircon and magnetite-bearing xenolith from Khao Wua, near Chanthaburi in Thailand, conclusively demonstrates a common origin for the sapphire, zircon and magnetite found in alluvial deposits in the Chanthaburi gem fields. The original aluminium- and titanium-rich octahedral magnetite crystal in the xenolith exsolved into hercynite, magnetite and hematite during cooling. It includes minor anhedral jarosite–alunite, possibly originating as an iron-sulphide-rich immiscible liquid. Uranium-lead isotope dating of zircon in the xenolith gives an age of 1–2 (± <1) million years (Ma). This falls within fission track ages for alluvial zircons (2.57 ± 0.20 Ma) from the Chanthaburi—Trat gem fields and within the potassium-argon ages of 0.44 to 3.0 Ma for the alkali basaltic volcanism in the Chanthaburi Province. These data suggest a common origin for sapphire, zircon and magnetite, and link them with the processes involved in alkali basaltic magma generation. The high iron and zirconium, low magnesium, and the inferred sulphides suggest pegmatite-like crystallization in an incompatible-element enriched, silica-poor magma (partial melt or fractionation product) in the deep crust or upper mantle. Etch features on exposed surfaces of the xenolith indicate that it was transported out of its equilibrium environment by the rise of later magma.
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Zhao, Shan Shan, Chao Liu, Xiu Jie Ji, Song Li, and Dong Xia Ma. "Synthesis of Ordered Lamellar Nanostructured Zirconia via SDS Template." Advanced Materials Research 178 (December 2010): 296–99. http://dx.doi.org/10.4028/www.scientific.net/amr.178.296.
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The ordered lamellar nanostructured zirconias were prepared via atmospheric reflux and hydrothermal hybrid method in ethanol-water system by using zirconium oxychloride as zirconium source and sodium dodecyl sulfonate (SDS) as template agent, which were characterized by X-ray diffraction (XRD). The results showed that the ordered lamellar nanostructured zirconias were composed of tetragonal phase for 110 and 125°C and tetragonal/monoclinic phase for 140 and 155°C. As the hydrothermal temperature raised, the monoclinic phase began to appear, and the crystallization is promoted, but the ordered lamellar nanostructure was shrinking prior to expanding in size, ranged from 1.33 to 1.55 nm, and tended to decrease in amount gradually. For the sample prepared at 110°C, the Fourier-transform infrared spectroscopy (FT-IR) pattern demonstrated that the inorganic phase is tetragonal zirconia and there remain small amount of template SDS. And the calcined lamellar nanostructure with a 1.2 nm periodicity was observed by transmission electron microscopy (TEM). This indicates the lamellar structure shrunk from 1.51 to 1.2 nm and was preserved after calcination at 500°C, showing good thermal stability.
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Laurent, Oscar, Jean-François Moyen, Jörn-Frederik Wotzlaw, Jana Björnsen, and Olivier Bachmann. "Early Earth zircons formed in residual granitic melts produced by tonalite differentiation." Geology 50, no. 4 (December 16, 2021): 437–41. http://dx.doi.org/10.1130/g49232.1.
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Abstract The oldest geological materials on Earth are Hadean (>4 Ga) detrital zircon grains. Their chemistry and apparently low Ti-in-zircon temperatures (≤700 °C) are considered to be inconsistent with crystallization in a magma of the tonalite-trondhjemite-granodiorite (TTG) suite, although these are the dominant Archean (4.0–2.5 Ga) silicic rocks. Using a new data set of trace element contents in zircons from Paleoarchean Barberton TTGs (South Africa) and thermodynamic modeling, we show that these zircons have crystallized at near-solidus conditions from a compositionally uniform granitic melt. This melt is residual from the crystallization of a less evolved (tonalitic) parent and thereby shows major and trace element compositions different from bulk TTG rocks. A global compilation reveals that most Hadean detrital and Archean TTG-hosted grains share a peculiar zircon trace element signature that is distinct from the chemical trends defined by Phanerozoic zircons. Our model shows that the low Ti contents of early Earth zircons reflect crystallization at higher temperatures (720–800 °C) than initially inferred due to lower modeled TiO2 activity in the melt relative to previous estimates. We therefore propose that near-solidus zircon crystallization from a chemically evolved melt in a TTG-like magmatic environment was the dominant zircon-forming process on the early Earth.
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Lee, Jeong Han, Da Som Kang, Min Kuk Moon, and Sung Kil Hong. "Separating Technology of Pure Zirconia from Zircon-Sand by the Ar-H2 Arc Plasma Fusion and the Microwave Leaching." Materials Science Forum 879 (November 2016): 1080–85. http://dx.doi.org/10.4028/www.scientific.net/msf.879.1080.
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Zirconia (ZrO2) has excellent properties such as high toughness, high strength, thermal stability and high corrosion resistance. Thus, recent zirconia has been spotlighted as a dental material. Most of pure zirconia has been separated from zircon sand (ZrSiO4) by wet refining process which is very complex and not an environmental. The arc plasma fusion method has the advantages as a sustainable process that can easily and quickly get very good fine and high pure powders from the original materials compared with traditional wet method. In this study, zircon sand is separated into zirconia and silica by using the Ar-H2(hydrogen) arc plasma refining. And then silica is removed from it by the microwave leaching method to produce a high pure zirconia. Argon gas, hydrogen gas, copper anode and tungsten cathode are used for the plasma arc generation. To facilitate zirconia and silica separation, carbon of 1-3molar ratios are added with zircon sand. Plasma melting were sequentially conducted two processes. After a reduction process using Ar gas only, it was refined using a mixed gas of Ar-H2. After melting and water cooling in chamber, the solid phases composed with zirconia and silica were obtained at 240 ̊C, and 20% sulfuric acid solution was used as the leaching materials to obtain a high purity zirconia (more than 99%).
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SHUMLYANSKYY, L. V., V. KAMENETSKY, and B. V. BORODYNYA. "Age and Composition of Zircons From the Devonian Petrivske Kimberlite Pipe of the Azov Domain, the Ukrainian Shield." Mineralogical Journal 43, no. 4 (2021): 50–55. http://dx.doi.org/10.15407/mineraljournal.43.04.050.
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Results of a study of U-Pb and Hf isotope systematics and trace element concentrations in five zircon crystals separated from the Devonian Petrivske kimberlite are reported in the paper. Four zircons have yielded Paleoproterozoic and Archean ages, while one zircon grain gave a Devonian age of 383.6±4.4 Ma (weighted mean 206Pb/238U age). The Precambrian zircons have been derived from terrigenous rocks of the Mykolaivka Suite that is cut by kimberlite, or directly from the Precambrian rock complexes that constitute continental crust in the East Azov. The Devonian zircon crystal has the U-Pb age that corresponds to the age of kimberlite emplacement. It is 14 m.y. younger than zircon megacrysts found in the Novolaspa kimberlite pipe in the same area. In addition, Petrivske zircon is richer in trace elements than its counterparts from the Novolaspa pipe. Petrivske and Novolaspa zircons crystallized from two different proto-kimberlite melts, whereas the process of kimberlite formation was very complex and possibly included several episodes of formation of proto-kimberlite melts, separated by extended (over 10 M.y.) periods of time.
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Liu, Chao, Xiangdong Chang, Beilei Sun, and Fangui Zeng. "New Insight into the Depositional Age of No. 6 Coal in Heidaigou Mine, Late Paleozoic Jungar Coalfield, Inner Mongolia, China." Sustainability 14, no. 10 (May 21, 2022): 6297. http://dx.doi.org/10.3390/su14106297.
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Coal deposits can provide novel stratigraphic markers for reconstructing the evolution history of a sedimentary basin and correlating sedimentary successions. Age dating was conducted on zircons harvested from the No. 6 coal seam within the Heidaigou Mine, Inner Mongolia. Two-kilogram samples were taken, and the recovered zircons were analyzed for U–Pb isotopic and rare earth elements (REE). The REE results of the zircon grains showed that all the zircon grains were enriched in heavy rare earth elements (HREE) but depleted in light rare earth elements (LREE). In addition, zircons from the No. 6 coal seam had strongly positive Ce (Ce/Ce* = 2.4–224.6) and strongly negative Eu anomalies (Eu/Eu* = 0.1–0.6). Combined with the clear oscillatory zones in the cathodoluminescence images, all the zircon grains of the No. 6 coal were characteristic of zircons with magmatic origins. The 206Pb/238U ages of 34 zircon grains produced a narrow age population of 303–286 Ma, with a weighted average age of 293.0 ± 1.5 Ma (mean-squared weighted deviation = 1.5). Therefore, we infer that the No. 6 coal in the Heidaigou Mine was deposited during the Early Permian, and the Carboniferous–Permian boundary should be located stratigraphically lower than the No. 6 coal. The zircon U–Pb geochronology is a useful tool to determine the depositional ages of non-marine-influenced coal.
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Qiu, Kunfeng, Haocheng Yu, Mingqian Wu, Jianzhen Geng, Xiangkun Ge, Zongyang Gou, and Ryan D. Taylor. "Discrete Zr and REE mineralization of the Baerzhe rare-metal deposit, China." American Mineralogist 104, no. 10 (October 1, 2019): 1487–502. http://dx.doi.org/10.2138/am-2019-6890.
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Abstract Although REE (lanthanides + Sc + Y) mineralization in alkaline silicate systems is commonly accompanied with Zr mineralization worldwide, our understanding of the relationship between Zr and REE mineralization is still incomplete. The Baerzhe deposit in Northeastern China is a reservoir of REE, Nb, Zr, and Be linked to the formation of an Early Cretaceous, silica-saturated, alkaline intrusive complex. In this study, we use in situ laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analyses of zircon and monazite crystals to constrain the relationship between Zr and REE mineralization at Baerzhe. Three groups of zircon are identified and are differentiated based upon textural observations and compositional characteristics. Type Ia zircons display well-developed oscillatory zoning. Type Ib zircons are darker in cathodoluminescence images and have more irregular zoning and resorption features than type Ia zircons. In addition, type Ib zircons can locally occur as overgrowths on type Ia zircons. Type II zircons contain irregular but translucent cores and rims with oscillatory zoning that are murky brown in color and occur in aggregates. Textural features and compositional data suggest that types Ia and Ib zircon crystallized at the magmatic stage, with type Ia being least-altered and type Ib being strongly altered. Type II zircons, on the other hand, precipitated during the magmatic to magmatichydrothermal transition. Whereas the magnitude of the Eu anomaly is moderate in the barren alkaline granite, both magmatic and deuteric zircon exhibit pronounced negative anomalies. Such features are difficult to explain exclusively by feldspar fractionation and could indicate the presence of fluid induced modification of the rocks. Monazite crystals occur mostly through replacement of zircon and sodic amphibole; monazite clusters are also present. Textural and compositional evidence suggests that monazite at Baerzhe is hydrothermal. Types Ia and Ib magmatic zircon yield 207Pb-corrected 206Pb/238U ages of 127.2 ± 1.3 and 125.4 ± 0.7 Ma, respectively. Type II deuteric zircon precipitated at 124.9 ± 0.6 Ma. The chronological data suggest that the magmatic stage of the highly evolved Baerzhe alkaline granite lasted less than two million years. Hydrothermal monazite records a REE mineralization event at 122.8 ± 0.6 Ma, approximately 1 or 2 million years after Zr mineralization. We therefore propose a model in which parental magmas of the Baerzhe pluton underwent extensive magmatic differentiation while residual melts interacted with aqueous hydrothermal fluids. Deuteric zircon precipitated from a hydrosilicate liquid, and subsequent REE mineralization, exemplified by hydrothermal monazite, correlates with hydrothermal metasomatic alteration that postdated the hydrosilicate liquid event. Such interplay between magmatic and hydrothermal processes resulted in the formation of discrete Zr and REE mineralization at Baerzhe.
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Wang, Xiao Bei, Yuan Hua Lin, and Xu Liang Deng. "Preparation and Characterization of Functional Gradient Porous ZrO2 Ceramics." Key Engineering Materials 519 (July 2012): 287–90. http://dx.doi.org/10.4028/www.scientific.net/kem.519.287.
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Porous zirconium dioxide (ZrO2) ceramics has been widely used in biomedicine, heat-insulation and piezoelectric actuators. In this study, a kind of porous ZrO2 ceramics with the gradient porosity and pore sizes was designed to be a composite lamellar material. The porosity and pore size change regularly through the thickness of the layers. This porous lamellar zirconic material has been prepared by the solid state reaction consisting of yttria-stabilized zirconia (YSZ) and stearic acid (SA) powders. The porosity and pore size can be tuned by the addition of SA. The mechanical properties of the graded porous ZrO2 have been studied in detail. The results show that the mechanical characteristics of the gradient porous ZrO2 can be controlled by changing the porosity and pore size.
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He, Yong Wu, Jing Long Bu, Rui Sheng Wang, Dong Mei Zhao, Jun Xing Chen, Li Xue Yu, and Zhi Fa Wang. "Sintering Properties of Fused Silica/Nano-Zirconia Composite Ceramic." Advanced Materials Research 750-752 (August 2013): 81–84. http://dx.doi.org/10.4028/www.scientific.net/amr.750-752.81.
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Zirconyl chloride was used as zirconium source and fused silica particles were used as main raw material. First of all, the composite powders were prepared by wet chemical synthesis using ammonia as the precipitator and polyethylene glycol as the dispersant. Then, fused silica nanozirconia composite ceramic containing nanometer particle zirconia with different contents (5%, 15%, 25% and 35%) were fabricated in reduction atmosphere at 1300°C, 1350°C and 1400°C for 1 h. The bulk density and bending strength were measured, microstructure was observed by SEM. The result indicated bulk density and bending strength of composite ceramic increase and microstructure becomes denser with content of zirconia increasing. Bulk density of composite ceramic increases and bending strength which reaches maximum at 1350°C firstly increases then decreases with the increase of sintering temperature. Both high sintering temperature and nanozirconia possessing high energy interface can improve the composite ceramic sintering.
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Pantoja, Heliana, and Marcondes Costa. "HEAVY MINERALS AND ZIRCON MORPHOLOGY: PROXIES BETWEEN RONDON DO PARÁ BAUXITES AND ITAPECURU ROCKS." Boletim do Museu de Geociências da Amazônia 9, no. 1 (June 30, 2022): 1–30. http://dx.doi.org/10.31419/issn.2594-942x.v92022i1a1ykk.
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The Eastern Amazon bauxite districts are located in the domain of the sedimentary rocks of the Itapecuru Group, which are considered to be their probable parent rocks. To assist in the elucidation, it was investigated the heavy minerals from Rondon do Pará bauxites. The assemblage is formed by ultrastable minerals, both in the Itapecuru and in the bauxite in similar concentrations: zircon, tourmaline, rutile and staurolite. They showed wide varieties of shapes, textures and structures, particularly for zircons, that suggest different sources of provenance. The euhedral zircons in general display the bipyramids {101} and the prisms {100}, which correspond to the S and P zircons, indicative of alkaline granites as source rocks for the Itapecuru, and that in turn are in the bauxite profile. Zircon ́s cathodoluminescences also similarly indicate different sources. They also exhibit variable concentrations of Zr, Hf, Th, U, Nb and Y, but the Zr/Hf ratios are quite constant. Therefore, the Zr/Hf ratios and the do-main of S-types and P zircons, both in the Itapecuru and in the bauxites, demonstrate that in fact its rocks, specifically those that occupied the current bauxite profile, were their parent rocks, thus strengthening the link between the two, bauxite and Itapecuru rocks. Keywords: cathodoluminescence; typology of zircon; zircon chemistry.
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Yaroshenko, V., and D. S. Wilkinson. "Phase Evolution During Sintering of Mullite/zirconia Composites Using Silica-coated Alumina Powders." Journal of Materials Research 15, no. 6 (June 2000): 1358–66. http://dx.doi.org/10.1557/jmr.2000.0198.
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Mullite-based composites can be made by an in situ reaction process using silica-coated alumina (SCA) powder as a mullite precursor. In this paper we present the combined effects of zirconia and premullite seeds on the crystallization process and microstructure development. When zirconia is added without seeding, mullite formation proceeds through the formation of transient zircon. This phase provides a lower energy barrier for mullite nucleation and thus lowers the mullitization temperature. The presence of yttria as a stabilizer in zirconia reduces the activation energy for zircon formation and thus promotes the transient reaction. The addition of premullite seeds results in the nucleation of mullite from alumina and silica, and zircon does not form. At low seeding levels mullitization remains nucleation-controlled; however, once the seeding level exceeds 1–2%, this is no longer the case.
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Belhouchet, H., H. Makri, M. Hamidouche, N. Bouaouadja, V. Garnier, and G. Fantozzi. "Multiphase composites obtained by sintering reaction of boehmite and zircon part I: Development and microstructural characterization." Science of Sintering 46, no. 3 (2014): 291–306. http://dx.doi.org/10.2298/sos1403291b.
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In this work, different composites (zircon-mullite, zirconia-mullite-zirconia, mullite-zirconia and alumina-zirconia-mullite) were developed by reactive sintering of a powder mixture of boehmite (AlOOH)) and zircon (ZrSiO)4. These powder mixtures were mixed and ground by ball milling and then pressed in cylindrical form. Finally, the green specimens were sintered in air during 2 hours between 1400?C and 1600?C, with a heating and cooling rate of 5?C/min. The dilatometric curves show that there are several microstructural transformations in these mixtures. X-rays diffraction spectra showed formation of several composites depending on the initial conditions (% of boehmite and zircon and sintering temperature). The micrographic observations of the samples confirmed the presence of various phases. <br><br><font color="red"><b> This article has been retracted. Link to the retraction <u><a href="http://dx.doi.org/10.2298/SOS150330002E">10.2298/SOS150330002E</a><u></b></font>
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Krasnobaev, A. A., P. M. Valizer, and N. N. Farrakhova. "Zircons of fenites of Ilmeno-Vishnevogorsky Complex (Southern Urals)." LITHOSPHERE (Russia) 21, no. 3 (July 8, 2021): 306–22. http://dx.doi.org/10.24930/1681-9004-2021-21-3-306-322.
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Research subject. U-Pb zircon dating, as well as a petrological and geochemical study of pyroxene-amphibole-, pyroxeneamphibole- biotite- and biotite-bearing fenites from the Central Alkaline Band Ilmeno-Vishnevogorsky Complex.Methods. The age of zircons was determined by an ion mass spectrometer (SHRIMP II, Centre of Isotopic Research VSEGEI). The content of REE and trace elements was estimated by secondary ion mass spectrometer methods (CAMECA IMS-4F, Valiev Institute of Physics and Technology RAS).Results. The mineralogical and geochemical (U, Th, REE) features of zircons, as well as fenites, reflect their polygenic-polychronous nature. Most zircon crystals have a metastable matrix and are characterized by averaged REE contents between igneous and hydrothermal types. These crystals are distinguished from magmatic zircons by high LREE contents and low values of Ce anomalies, and from hydrothermal zircons – by differentiated REE distribution spectra. Three ages of zircon were established: 2066–1686 (PR1), 425–404 (S2) and 284–266 (P1) Ma. PR1 zircons reflect the primary features and the degree of changes in the fenite substrate. S2 zircons, limited only to the biotite- bearing fenite, correspond to the age of the miaskite formation process. The P1 zircons clearly reflect the metasomatic process of fenitization initiated by late shear deformations. The temperature of the phenitization processes (based on the Ti content in zircons) was estimated at 630–670°C for S2 and ≤ 600°C for P1 fenites, respectively.Conclusions. Central Alkaline Band fenites were formed by the metasomatic process of PR1 substrate fenitization in the late stage (P1) of shear strains, which are widely expressed in the Ilmeno-Vishnevogorsky Complex.
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Liu, Chaohui, Guochun Zhao, Fulai Liu, and Jia Cai. "A Palaeoarchean–Mesoarchean micro-continent entrained in the Jiao-Liao-Ji Belt at the southeastern North China Craton: evidence from the zircon record in the Bengbu area." Geological Magazine 156, no. 9 (March 18, 2019): 1565–86. http://dx.doi.org/10.1017/s0016756818000869.
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AbstractThe Bengbu area in the southeastern North China Craton (NCC) consists predominantly of Archean–Palaeoproterozoic (gneissic) granitoids with minor supracrustal rocks (the Fengyang and Wuhe groups). This study presents new zircon laser ablation – inductively coupled plasma – mass spectrometry U–Pb and Lu–Hf isotopic data and trace-element contents for these granitoids, which improve understanding the Archean–Palaeoproterozoic crustal evolution of the NCC. Magmatic zircon U–Pb data reveal that zircons in the (gneissic) granitoids were generated by multi-stage events at 2.93, 2.73, 2.53–2.52 and 2.18–2.13 Ga. Metamorphic zircon U–Pb data obtained from these rocks show two distinct metamorphic ages of 2.49–2.52 and 1.84 Ga, suggesting that the Bengbu area experienced a regional metamorphic event at the end of the Neoarchean Era and encountered reworking by a tectonothermal event associated with the formation of the Palaeoproterozoic Jiao-Liao-Ji Belt. Trace-element compositions of magmatic zircons reveal the highest Ti concentrations (8.08±3.38 ppm) and growth temperatures (718±44 °C) for the zircons aged 2.13–2.17 Ga and an increase in zircon U/Yb ratios from 2.93 Ga (0.34±0.12) through 2.73 Ga (0.96±0.42) to 2.53 Ga (1.05±0.46), but an evident decrease at 2.17–2.13 Ga (0.61±0.40 ppm). Similar Palaeoarchean xenocrystic and detrital zircons with negativeɛHf(t) values, late Mesoarchean magmatic zircons with juvenile Hf isotopic features, early Neoarchean magmatic zircons with model ages of 2.9–3.0 Ga, and two regional metamorphic events at 2.52–2.48 and 1.88–1.80 Ga in the Bengbu and Jiaobei areas indicate a Palaeoarchean–Mesoarchean micro-continent entrained in the Jiao-Liao-Ji Belt at the southeastern NCC.
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Abbas, Abbas, Agus Triantoro, and Riswan Riswan. "STUDI PENGOLAHAN MINERAL ZIRCON (ZrO²) MENJADI ZIRCONIA PADA PT KALIMANTAN ZIRCON INDUSTRI DI DESA GOHONG KECAMATAN KAHAYAN HILIR KABUPATEN PULANG PISAU." Jurnal Himasapta 5, no. 2 (September 10, 2020): 25. http://dx.doi.org/10.20527/jhs.v5i2.2337.
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Konsentrat zircon di PT Kalimantan Zircon Industri diproses melalui metode pengolahan gravity consentration menggunakan meja goyang, magnetic separation, dan elektrostatic separation. PT Kalimantan Zircon Industri menarget produksi sebanyak 80 ton per hari pada shif siang mulai pukul (07.00 – 16.00 WIB) dan shif malam (16.00 – 01.00 WIB).Penelitian ini dilakukan dengan pengamatan secara langsung di lapangan dan mengkompilasi data tersebut dengan literatur berdasarkan teori yang berkaitan dengan pengolahan bahan galian khususnya mineral zircon menjadi zirconia. Peraturan Menteri Energi dan Sumber Daya Mineral Nomor 7 Tahun 2012 tanggal 6 Februari 2012 mengamanatkan bahwa pelaku usaha yang bergelut di bidang pengolahan mineral zircon diwajibkan melakukan peningkatan nilai tambah mineral melaui pengolahan dan pemurnian dengan kadar mineral zirconia berupa produk akhir 65,6 %. Rangkaian proses pengolahan ini dimulai dari pengolahan pada sluice box, meja goyang, magnetic separation, dan elektrostatic separation dan pengulangan pengolahan pada pada sluice box, meja goyang, magnetic separation, dan elektrostatic separation serta mengkaitkan pengaruh kecepatan air tipis pada permukaan meja goyang dan peningkatan feed dalam pencapaian target produksi 80 ton per hari dan menganalisid hubungan pencapaian target produksi tersebut dengan feed, material balance dan recovery.Dari hasil penelitian, sebanyak 86 ton material pasir zircon diperlukan untuk mendapatkan konsentrat zirconia 81,8 ton per hari, dengan kecepatan feed 2,384 kg/m, recovery 76,3 %, kecepatan aliran tipis air pada permukaan meja goyang 3,164 m/s, dan volume fluida 48,675 m/s. Kata-kata kunci : feed, konsentrat, pengolahan, zircon
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Leary, Ryan J., M. Elliot Smith, and Paul Umhoefer. "Mixed eolian–longshore sediment transport in the late Paleozoic Arizona shelf and Pedregosa basin, U.S.A.: A case study in grain-size analysis of detrital-zircon datasets." Journal of Sedimentary Research 92, no. 8 (August 22, 2022): 676–94. http://dx.doi.org/10.2110/jsr.2021.101.
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ABSTRACT Detrital-zircon U–Pb geochronology has revolutionized sediment provenance studies over the last two decades, and zircon has been successfully analyzed from nearly all sedimentary lithologies, depositional environments, and sediment grain sizes. However, despite the ubiquity of this method and the far-reaching interpretations supported by detrital-zircon data, few studies have investigated the potential role of zircon grain size on age spectra and provenance interpretation. In this study, we investigate the connections between sample grain size, zircon grain size, U–Pb age spectra, and interpreted provenance using 18 detrital-zircon samples (4999 individual grains) collected from Pennsylvanian–Permian strata in central and southern Arizona, USA. In these samples, there is no clear correlation between sample grain size and zircon grain size and no clear correlation between sample grain size and age spectra. However, when all grains are grouped by zircon minimum long-axis dimension, the abundance of some age groups is correlated to zircon grain size. In Pennsylvanian samples, < 400 Ma grains and 2500–3000 Ma zircons are more abundant in the finer fractions, and 1400–1900 Ma zircons are more abundant in coarser fractions of both Pennsylvanian and Permian samples. In Permian samples, 500–800 Ma zircons are most abundant in the finer fractions, and 2500–3000 Ma grains are concentrated in the coarser fractions. Based on changes in abundance and grain-size distribution of 500–800 Ma grains, we interpret a change in zircon provenance across the Pennsylvanian–Permian boundary that reflects regional climate and paleogeographic changes driven in part by the northward drift of Laurentia across the equator. Specifically, we interpret the concentration of 500–800 Ma zircons in Permian samples in central and southern Arizona to indicate that these grains were: 1) sourced from Gondwana, 2) deposited in, and subsequently eroded (recycled) from, Mississippian–Pennsylvanian strata in the Arkoma, Anadarko, and Fort Worth basins at the margins of Laurentia, and 3) finally transported into the Arizona study area as loess by easterly trade winds. This study serves as a case study in the value and interpretive power of basic grain-size characterization of detrital-geochronology datasets.
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Skublov, Sergey G., Aleksey V. Berezin, Xian-Hua Li, Qiu-Li Li, Laysan I. Salimgaraeva, Veniamin V. Travin, and Dmitriy I. Rezvukhin. "Zircons from a Pegmatite Cutting Eclogite (Gridino, Belomorian Mobile Belt): U-Pb-O and Trace Element Constraints on Eclogite Metamorphism and Fluid Activity." Geosciences 10, no. 5 (May 21, 2020): 197. http://dx.doi.org/10.3390/geosciences10050197.
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This report presents new data on U-Pb geochronology, oxygen isotopes, and trace element composition of zircon from a pegmatite vein crosscutting an eclogite boudin on Stolbikha Island, Gridino area, Belomorian mobile belt (BMB). The zircon grains occur as two distinct populations. The predominant population is pegmatitic and shows dark cathodoluminescence (CL); about a third of this population contains inherited cores. The second zircon population is typical of granulite and exhibits a well-defined sectorial (mosaic) zoning in CL. Both the inherited cores and sectorial in CL zircons appear to have been captured from metabasites as xenocrysts during the pegmatite vein formation. A U-Pb age of 1890 ± 2 Ma for the main zircon population is interpreted as the age of the pegmatite injection. This value is close to the age threshold for the BMB eclogites (~1.9 Ga) and unambiguously defines the upper age limit for the eclogite metamorphism. The pegmatite formation is thus related to partial melting events that occurred during the retrograde amphibolite-facies metamorphism shortly after the eclogitization. A U-Pb date of 2743 ± 10 Ma obtained for the sectorial in CL zircons is considered as the age of the granulite-facies metamorphism established previously within the BMB. The values of δ18O in the zircon populations overlap in a broad range, i.e., δ18O in the pegmatitic zircons varies from 6.1‰ to 8.3‰, inherited cores show a generally higher δ18O of 6.7–8.8‰, and in the captured granulitic zircons δ18O is 6.2–7.9‰. As a result of fluid attack during the final stage of the pegmatite vein formation, the composition of the pegmatitic zircons in terms of non-formula elements (REE, Y, Ca, Sr, Ti) has become anomalous, with the content of these elements having been increased by more than tenfold in the alteration zones. Our data provide new constraints on the timing of eclogite metamorphism within the BMB and show that the late-stage pegmatite-related fluids exerted a very pronounced influence on trace element abundances in zircon, yet had no significant impact on the isotopic composition of oxygen.
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Kanygina, N. A., A. A. Tretyakov, K. E. Degtyarev, K. N. Pang, K. L. Van, H. Y. Lee, and J. V. Plotkina. "First results of dating detrital zircons from the late precambrian quartzite-schist sequences of Chu block (Southern Kazakhstan)." Доклады Академии наук 489, no. 1 (November 10, 2019): 57–61. http://dx.doi.org/10.31857/s0869-5652489157-61.
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U-Pb geochronological studies of detrital zircons from quartzite-schist sequences of the Akbastau Formations of the Chu block (northwest of the Chu-Kendyktas terrane, Southern Kazakhstan) have been provided. The concordant ages of detrital zircons are predominantly within the intervals of 1672-2115 Ma with peaks at 1697, 1780, 1857 and 2066 Ma. Individual zircon grains display ages of 2291-2332 Ma with peaks at 2303 and 2322 Ma. Neoarchean ages 2608-2747 with peak at 2681 Ma characterize another significant zircon population. The lower limit of deposition for the Akbastau Formations of the Chu block, corresponding to the youngest statistically significant zircon population, is estimated at 1,7 billion years.
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Huijsmans, Jasper R., Maartje Hamers, Martyn R. Drury, and James K. W. Lee. "Recrystallisation and Trace-Element Mobility in Zircons: Implications for U-Pb Dating." Minerals 12, no. 12 (November 23, 2022): 1489. http://dx.doi.org/10.3390/min12121489.
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Complex microstructures of zircon recrystallisation have been discovered in igneous and metamorphic zircons from the Jack Hills Metasedimentary Belt in Western Australia, and the granitic injection complex of Harris in north-west Scotland. Cathodoluminescence (CL), electron backscatter diffraction (EBSD) and wavelength dispersive spectroscopy (WDS) analysis reveal that recrystallisation in the studied zircons is often characterised by (1) translation, bending and fading of the oscillatory zoning; (2) structural recovery of the zircon; (3) an enrichment in Hf and depletion in Y in recrystallised zircon; and (4) the formation of a recrystallisation interface with a minor (<2°) misorientation. A new, composite recrystallisation model in which trace element and dislocation migration occurs shortly after crystallisation during magmatic cooling and pipe diffusion along dislocation arrays formed by the accumulation of dislocations allows enhanced diffusion to enrich Hf and leach U, Pb and Y. After the recrystallisation event, subsequent metamictization of primary zircon (typically with oscillatory zoning) creates zones that can structurally recover through a diffusion-reaction re-equilibration mechanism, resulting in further trace-element mobility. These mechanisms can create complex microstructures in zircons, suggesting that a detailed understanding of the crystallisation and recrystallisation history of a zircon may be required to accurately interpret its U-Pb ages.
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Wijayanti, Rizky Berliana, Irna Rosmayanti, Kristanto Wahyudi, Eneng Maryani, Hernawan Hernawan, and Rifki Septawendar. "Preparation of Magnesia Partially Stabilized Zirconia Nanomaterials from Zirconium Hydroxide and Magnesium Carbonate Precursors Using PEG as a Template." Crystals 11, no. 6 (June 1, 2021): 635. http://dx.doi.org/10.3390/cryst11060635.
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Stabilized zirconia is a promising material due to its great physical and chemical properties, and thermal stability. In this work, MgO was used as a stabilizer in ZrO2 to obtain Magnesia Partially Stabilized Zirconia (MSZ) nanomaterials assisted with PEG as a template through conventional mixing process. Zirconium hydroxides prepared from local zircon and MgCO3 were used as MSZ precursors. Meanwhile, the stabilizer concentration was varied from 1 to 4 wt% of ZrO2. The effect of the stabilizer concentration and the calcination temperature to the crystallinity and the morphological properties of the MSZ nanoparticles were studied using X-ray diffraction and scanning and transmission electron microscopy. The ZrO2 content in the zirconium hydroxides precursors is accounting 89.52 wt% of the total and exhibits the dominant m-phase at 1000 °C. Meanwhile, the tetragonal and the monoclinic phases were formed in all MSZ samples at a temperature of 800–1000 °C. The as-synthesized MSZ samples show typical FT-IR spectra, consisting of the metal–oxygen bonds at below 500 cm−1 and the organic functional groups ranging at 1000–3000 cm−1. The ZrO2 morphologies exhibit spherical-like shapes with elongated agglomeration at 800 °C. In addition, the average particle sizes of the final product ranges from 20 to 50 nm. At a sintering temperature of 1500 °C, MSZ samples show the monoclinic phase of ZrO2 and densities in the range of 3.95–4.14 g/cm3.
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Piper, David J. W., Georgia Pe-Piper, Mike Tubrett, Stavros Triantafyllidis, and Greg Strathdee. "Detrital zircon geochronology and polycyclic sediment sources, Upper Jurassic – Lower Cretaceous of the Scotian Basin, southeastern Canada 1This article is one of a series of papers published in this CJES Special Issue on the theme of Mesozoic–Cenozoic geology of the Scotian Basin." Canadian Journal of Earth Sciences 49, no. 12 (December 2012): 1540–57. http://dx.doi.org/10.1139/e2012-072.
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Sources of Tithonian–Albian sediment in the Scotian Basin are interpreted from detrital zircon geochronology to test previous hypotheses about the sources and pathways of sediment to thick deltaic successions that are important hydrocarbon reservoirs. Sediment provenance influences reservoir quality, but also provides information on tectonism during rifting of the North Atlantic Ocean. More than 760 zircons were dated by laser ablation U–Pb methods from nine offshore wells and one borehole on land and were characterized by external morphology, internal zoning, and Th/U ratio. A Meguma terrane source to the LaHave Platform was confirmed by peaks in detrital zircon abundance at 550–650 Ma, 1.0–1.2 Ga, and ∼2.1 Ga. Samples from the Sable Subbasin show a large peak in detrital zircon abundance at ∼1050 Ma, with lower peaks from 400–650, ∼1480, ∼1650, ∼1860 Ma and 2.7 Ga, characteristic of inboard Appalachian terranes of Laurentide affinity. Many late Paleozoic to Neoproterozoic zircons are euhedral or subhedral, and apparently first cycle, as are a few older zircons that indicate transport from the rising rift shoulder in southern Labrador as far north as the Makkovik Province (∼1860 Ma). About half the zircons are rounded and polycyclic. Samples from the Abenaki Subbasin are similar, but late Paleozoic to Neoproterozoic zircons are rare and ∼40% of the Mesoproterozoic zircons are subhedral, implying a different Laurentide source through the Humber valley. Euhedral–subhedral unzoned zircons yielded two groups of Cretaceous dates: ∼105 Ma from the Cree Member, and ∼120 Ma from the Missisauga Formation.
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Tokuda, Makoto, Akira Yoshiasa, Hiroshi Kojitani, Saki Hashimoto, Seiichiro Uehara, Tsutomu Mashimo, Tsubasa Tobase, and Masaki Akaogi. "The importance of cation–cation repulsion in the zircon–reidite phase transition and radiation-damaged zircon." Mineralogical Magazine 83, no. 4 (May 22, 2019): 561–67. http://dx.doi.org/10.1180/mgm.2019.27.
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AbstractSingle crystals of synthetic reidite and natural radiation-damaged zircon from Okueyama, Japan were investigated using X-ray diffraction. The pressure-induced zircon–reidite transition is described by the twisting and translations of SiO4 tetrahedra with disappearance of the SiO4–ZrO8 shared edges. The lattice of radiation-damaged zircons expands mainly from α-decays of radioactive elements such as U and Th. Although old radiation-damaged zircons show anomolous lattice distortion, young radiation-damaged zircons do not show such distortions. These distortions are caused by thermal recovery that suppresses the Si4+–Zr4+ repulsion between the SiO4 tetrahedron and ZrO8 dodecahedron. These changes in structure can be understood by considering the cation–cation repulsion between the SiO4–ZrO8 shared edges.