Thorium Phosphates Orthorhombic

Thorium phosphates, method for preparing same, and use ...

Thorium phosphate according to wherein said thorium phosphate crystallizes in an orthorhombic system, space group Pbcm and Z=2. 4. Process for the preparation of thorium phosphate of formula Th.sub.4 P.sub.6 O.sub.23, comprising the steps of:

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Thorium(IV) nitrate - Wikipedia

The thorium atom has 12-coordination, with four bidentate nitrate groups and four water molecules attached to each thorium atom. To obtain the anhydrous thorium(IV) nitrate, thermal decomposition of Th(NO 3) 4 ·2N 2 O 5 is required. The decomposition occurs at 150-160 °C. Properties. Anhydrous thorium nitrate is a white substance.

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Thorium phosphates, method for preparing same, and use ...

Sep 14, 1999· The invention relates to novel thorium phosphates, their preparation process and their use for the storage of radioactive products. These novel thorium phosphates comply with the formulas Th 4 P 6 O 23 (I) or Th 4-x M 4x /v P 6 O 23 (III) in which: . M is a monovalent, divalent, trivalent or tetravalent cation,

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Thermal synthesis and structural characterization of the ...

The authors are grateful to the FEDER and Spanish MINECO for financial support under projects MAT 2010-15094 and MAT 2011-27573-C04 and Factoría de Cristalización—Consolider Ingenio 2010.

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Thorium phosphates prepared by insolubilization of soluble ...

Environmental pollution stemming from the industrial discharge and/or storage of water-soluble thorium compounds is avoided by converting same into essentially innocuous water-insoluble thorium phosphates, notably orthorhombic thorium phosphates, by (i) reacting such water-soluble thorium compounds, e.g., the nitrates and/or chlorides, with a base, for example aqueous ammonia, in an …

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Uranium Element Facts and Properties - ThoughtCo

Mar 31, 2019· Uranium is of great importance as a nuclear fuel. Nuclear fuels are used to generate electrical power, to make isotopes, and to make weapons. Much of the internal heat of the earth is thought to be due to the presence of uranium and thorium. Uranium-238, with a half-life of 4.51 x 10 9 years, is used to estimate the age of igneous rocks ...

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Grayite - Wikipedia

While previous work has identified grayite as a pseudohexagonal orthorhombic member of the rhabdophane group along with ningyoite, more contemporary work seems to maintain a hexagonal crystal structure. These hydrated phosphate minerals often include radioactive elements such as thorium, uranium, and cerium.

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Sintering of β-Thorium−Uranium(IV) Phosphate−Diphosphate ...

Introduction zirconium phosphates,17 the synthesis and the charac- terization of thorium and uranium phosphate com- The disposal of nuclear waste for an underground pounds were studied for several years.18-23 These repository is currently considered as a …

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Crystal Orthorhombic 2 - globalconsultancy.in

• For a crystal to be orthorhombic it has to have either: – 3-2 fold axis perpendicular to each other – 1-2 fold axis plus two mirror planes Contact: Click here Preface Crystal structure is one of the most important aspects of materials science and engineering as many properties of …

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From thorium phosphate hydrogenphosphate hydrate to {beta ...

{beta}-Thorium phosphate diphosphate ({beta}-TPD), considered as a very promising radwaste storage material, was obtained from thorium phosphate hydrogenphosphate hydrate (TPHPH) precursor through dehydration and hydrogen phosphate condensation. The structures of TPHPH, intermediate {alpha}-thorium ...

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Environmental chemistry of uranium - heja.szif.hu

Environmental chemistry of uranium ... orthorhombic, tetragonal and in body-centered cubic ones [28]. Uranium exhibits a high melting point ... phosphates, silicates, arsenates, vanadates and oxyhydroxides, several of which may occur simultaneously at the same locality. The amount of uranium released to ground- or surface waters from these ...

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Th4(PO4)4P2O7, a New Thorium Phosphate: Synthesis ...

The chemistry of thorium phosphate reported in the literature has been found to be erroneous. It was reconsidered in terms of careful chemical preparations and specific analytical methods. Special attention has been paid to the atom ratio value referred to r = thorium/phosphorus, which was experimentally fixed in order to obtain the correct composition of the final compound.

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From thorium phosphate hydrogenphosphate hydrate to ...

1 From thorium phosphate hydrogenphosphate hydrate to - thorium phosphate diphosphate: structural evolution to a radwaste storage ceramic Gilles Wallez,a* Nicolas Clavierb, Nicolas Dacheuxb, Michel Quarton,a Wouter van Beekc a Université Pierre et Marie Curie-Paris6, CNRS UMR 7574, Chimie de la Matière Condensée de Paris, 4 place Jussieu, Paris, F-75005 France

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Calcium thorium phosphate (Whitlockite-type mineral ...

The crystal structure of a new calcium thorium phosphate has been refined by the full-profile Rietveld method using X-ray powder diffraction data. The sample has been synthesized by the sol-gel technique. The phosphate has been identified by X-ray powder diffraction and IR spectroscopy. The refined ...

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Crystallographic Study of Uranium-Thorium Bearing Minerals ...

bility at depth; uranyl phosphates and uranium adsorption onto clays and FeMn-oxides control uranium solubility near the surface. So, uranium may either move in solu- tion as complex ion, or like thorium, in a sorbed or detri- tal phase. 2. UO2 Most of the studies report mobilization in terms of oxidation state.

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Uranous Phosphates - Atomistry

Uranous pyrophosphate, UP 2 O 7, may be obtained by heating uranous hydrogen phosphate, UH 2 (PO 4) 2.5H 2 O, in a current of carbon dioxide; or more readily, by calcining the uranyl salt, UO 2 H 4 (PO 4) 2.3H 2 O, in an atmosphere of hydrogen.The product is amorphous but becomes crystalline without change in composition on heating in a stream of hydrogen chloride.

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Thorium phosphates prepared by insolubilization of soluble ...

Apr 04, 1995· Environmental pollution stemming from the industrial discharge and/or storage of water-soluble thorium compounds is avoided by converting same into essentially innocuous water-insoluble thorium phosphates, notably orthorhombic thorium phosphates, by (i) reacting such water-soluble thorium compounds, e.g., the nitrates and/or chlorides, with a base, for example aqueous ammonia, …

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Thermal synthesis and structural characterization of the ...

Jul 20, 2014· Abstract. Polycrystalline thorium(IV) phosphate-triphosphate, Th 2 (PO 4)(P 3 O 10) (), was obtained by (NH 4) 2 Th(PO 4) 2 ·H 2 O heating from room temperature to 1,273 K. 1 crystallizes in the orthorhombic space group Pn2 1 a (a = 11.6846() Å, b = 7.1746() Å, c = 12.9320() Å, Z = 4). Combining powder synchrotron X-ray diffraction data and DFT geometry optimization, a structural …

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Characterization of the thorium phosphate ...

It was first dehydrated leading to the anhydrous thorium phosphate-hydrogenphosphate (TPHP, orthorhombic system with a = 21.229(2) Å, b = 6.661(1) Å and c = 7.031(1) Å at 220 °C) after heating between 180 and 200 °C.

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PEROVSKITE (Calcium Titanium Oxide) - Amethyst Galleries

Perovskite is an increasingly economically important, and in some rocks a rather common, mineral. It is sought after for its rare earth metal content. Often perovskite is enriched in cerium, niobium, thorium, lanthanum, neodymium and other rare earth metals.

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Crystallo graphic Miniature Models (Q - Z) - singlecrystal.eu

Crystallo graphic Miniature Models (Q - Z) Quartz . Two helices . SiO2. Large . SiO2. Large trigonal . SiO2. Ramsdellite. TiO2. Rhenium Oxide

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Characterization of the thorium phosphate ...

Request PDF on ResearchGate | Characterization of the thorium phosphate-hydrogenphosphate hydrate (TPHPH) and study of its transformation into the thorium phosphate-diphosphate (β …

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THORIUM PHOSPHATE-DIPHOSPHATE AS A CERAMIC FOR …

Among the solids synthesized, the thorium phosphate-diphosphate Th4(PO4)4P2O7 (TPD) was obtained through several ways of synthesis (using wet and dry chemistry methods) then characterized. The ab initio structure determination on powder and single crystal led to an orthorhombic unit cell (space group Pcam, Z = 2) with

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Mineral Commodity Report 17 - Rare Earths and Related …

number 21), also a Group IIIA transition metal, and thorium (atomic number 90), an element in the actinide series of the Periodic Table. Mineral Commodity Report 17 - Rare Earths and Related Elements REE are classified into two groups: the light or cerium subgroup, comprising the …

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Thorium(IV) nitrate | Revolvy

Anhydrous thorium nitrate is a white substance. It is covalently bound with low melting point of 55 °C. [3] The pentahydrate Th(NO)•5HO crystallizes with clear colourless crystals [7] in the orthorhombic system. The unit cell size is a=11.191 b=22.889 c=10.579 Å.

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Grayite | Wiki | Everipedia

Due to its thorium content, grayite displays a few radioactivity although it is only moderate and the mineral displays powder XRD peaks without any metamict-like effects. The colour of grayite is most commonly observed as a light to dark reddish brown but has additionally been observed as lighter yellows with greyish tints.

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Uranium - Wikipedia

Uranium is a chemical element with symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table.A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons.Uranium is weakly radioactive because all isotopes of uranium are unstable, with half-lives varying between 159,200 years and 4.5 billion years.

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Phosphate minerals - Revolvy

Phosphate rock is a general term that refers to rock with high concentration of phosphate minerals, most commonly of the apatite group. It is the major resource mined to produce phosphate fertilizers for the agriculture sector. Phosphate is also used in animal feed supplements, food preservatives, anti-corrosion agents, cosmetics, fungicides, ceramics, water treatment and metallurgy.

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Sintering of β-Thorium−Uranium(IV) Phosphate−Diphosphate ...

Pure and single phase thorium−uranium(IV) phosphate-diphosphate β-TUPD (orthorhombic form) dense pellets were prepared by two wet chemical routes from low-temperature precursors.

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From thorium phosphate hydrogenphosphate hydrate to β ...

β-Thorium phosphate diphosphate (β-TPD), considered as a very promising radwaste storage material, was obtained from thorium phosphate hydrogenphosphate hydrate (TPHPH) precursor through dehydration and hydrogen phosphate condensation.The structures of TPHPH, intermediate α-thorium phosphate diphosphate (α-TPD) and its hydrate (α-TPDH) have been resolved ab initio by Rietveld …

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