Thorium is a naturally occurring, slightly radioactive element. It is widely distributed in nature with an average concentration of 10.5 ppm Th in the upper earth's crust. In general, thorium occurs in …Web

Two non-radioactive surrogates, hafnium oxide and cerium oxide, together with radioactive thorium oxide were compared. Similarities in behaviour were observed for all three surrogates when calcined at the lowest temperature, 750°C but differences became more pronounced as the calcination temperature was increased to 950°C.Web

Thorium is a lanthanide (rare earth) material with potential nuclear power applications. It is presently used as a tungsten coating in electronic parts due to its high emission factor. In its fluoride and oxide forms, Thorium …Web

Thorium oxide, [radioactive material, low specific activity] is a white powder. Density 9.7 g / cm3. Not soluble in water. Used in high-temperature ceramics, gas mantles, nuclear fuel, flame spraying, crucibles, non-silicia optical glass, catalysis, filaments in incandescent lamps, cathodes in electron tubes and arc-melting electrodes.Web

Graphical Abstract Keywords Thorium fuel Ceramic microsphere Sol-Gel Hydrothermal treatment Polyvinyl alcohol Cracking fraction Highlights Intact high-quality external gelation-made ThO 2 ceramic microspheres were prepared. PVA was eliminated by hydrothermal degradation and then an easy thermal oxidation process. Hydrothermal-induced changes …Web

Thorium oxide, like other oxides of tetravalent cations (zirconium oxide, cerium oxide) is a material with predominant electrical conduction via O 2− ions [1], [3]. …Web

Thorium oxide: a new catalyst for methanol, isobutanol, and light hydrocarbon production from carbon monoxide and hydrogen. Applied Catalysis 1984, 10 (3), 313-316.Web

Crucibles were made from thorium oxide by casting from a slip made according to ceramic practice. The presence of cryolite in the slip insured its successful use. These were fired …Web

Thorium oxide finds application as catalyst, high temperature ceramic and high quality lenses [2]. In view of the extensive usage of uranium and thorium for various industrial purposes and potential risks presented by radionuclides for humans and the environment, precise determination of these metals in environmental, metallurgical, and ...Web

The invention belongs to a preparation method of nuclear fuel, and concretely relates to a preparation method of thorium-uranium mixed oxide ceramic microspheres. The method uses an internal gelation method, and comprises using an acid-lacking uranyl nitrate solution and thorium nitrate as raw materials, preparing sol, dispersing gelling, washing, drying, …Web

De-agglomeration of thorium oxalate – a method for the synthesis of sinteractive thoria. Journal of Nuclear Materials 2002, 306 (1), 1-9. DOI: 10.1016/S0022 …Web

Advanced ceramics – oxides and nitrides. An oxide is a chemical compound made up of oxygen combined with at least one other element. Most of the Earth's crust consists of …Web

Thorium oxide (ThO 2, M.P. 3220°C) has found limited use as a high-temperature specialty ceramic. Its high cost, radioactive properties, and poor thermal shock resistance have prevented widespread usage as a refractory. The primary source of thorium is monazite, which is a rate-earth phosphate containing 3 to 8% thoria.Web

Thorium: Image of camera lenses. The yellowed lens is due to thorium radioactivity and can be reversed by exposing the lens to UV light. CC BY-SA 2.0. ... Earlier uses of thorium include as a light source, by heating thorium oxide, in the production of ceramics and carbon arc lamps. The radioactive nature of thorium was first observed in 1898.Web

The test fuel, which is in the form of pellets composed of a dense thorium oxide ceramic matrix containing about 10% plutonium oxide as the "fissile driver," can also be made in existing ...Web

Editorial Note: For Federal Register citations affecting § 40.13, see the List of CFR Sections Affected in the Finding Aids section. 1 On July 25, 1983, the exemption of glass enamel or glass enamel frit was suspended. The exemption was eliminated on September 11, 1984. 2 The requirements specified in paragraphs (c) (5) (i) and (ii) of this ...Web

Journal Article: PROPERTIES OF THORIUM OXIDE CERAMICS. PROPERTIES OF THORIUM OXIDE CERAMICS. Full Record; Other Related Research; Authors: Curtis, C E; Johnson, J R Publication Date: Fri Feb 01 00:00:00 EST 1957Web

The thorium oxide powder was supplied by India Rare Earths and it was oxalate derived. It was found that the as received powders were not suitable for compacting directly. ... [29] Johnson, J.R. and Curtis, C.E. (1954) Properties of Thorium Oxide Ceramics. Interim Report ORNL 1809. [30] Johnson, J.R. and Curtis, C.E. (1954) Note on Sintering of ...Web

Thorium dioxide is a refractory ceramic material and is difficult to sinter to high density. Commercial powder starts to sinter in SPS under 70 MPa above 1000 °C and compaction is not finished at 1600 °C.In contrast, a 13 nm nanopowder synthesised via low temperature decomposition of thorium oxalate starts to sinter at ∼500 °C; the onset of …Web

In this study, a hydrothermal treatment (HT) at 200 °C was used to deal with the cracking of the external gelation-made thorium oxide (ThO 2) microspheres and the effects of HT on the composition, microstructure, and cracking fraction of the microspheres were investigated.The results showed that HT removed the light weight impurities such …Web

The thorium oxide powder was supplied by India Rare Earths and it was oxalate derived. It was found that the as received powders were not suitable for compacting directly. ... Properties of Thorium Oxide Ceramics. Interim Report ORNL 1809. Johnson, J.R. and Curtis, C.E. (1954) Note on Sintering of Thoria. Journal of the American Ceramic Society ...Web

Ceramics can be particularly radioactive if some compound of uranium (e.g., uranium oxide, sodium urinate) has been used to impart color (e.g., orange-red, green, yellow, black) to the glaze. It is widely known that uranium was used in the glaze of orange-red Fiesta dinnerware, but uranium glazes have also been used other types of ceramics ...Web

The ceramic uses of thorium oxide are listed. Bibliography Citing Literature Volume 25, Issue 5 March 1942 Pages 129-141 References Related InformationWeb

Thorium oxide is used as an industrial catalyst. Other uses for thorium include heat-resistant ceramics, aircraft engines, and in light bulbs. Thorium can be used as a source of nuclear power. It is about three times as abundant as uranium and about as abundant as lead, and there is probably more energy available from thorium than from both ...Web

Thoria ceramics in the form of 12-in. rods, 1.5 in. in diameter, and small (0.1-in.) pellets with CaO additions were made having densities up to 97% of theoretical; evaluation of the …Web

14.3.1.4.2 Thorium Oxide Nanostructures The preparation of nanocrystalline fine powder of ThO 2 with various methods has been achieved to reduce the cost of fabrication of thoria ceramic materials in the typical nuclear industry.Web

In nature, thorium is more abundant than uranium . Researchers are predicting that a future energy source could be thorium. Recently, a reported economic analysis of the thorium extraction process from monazite concluded that for ten tons of thorium oxide production the minimum cost of ~ $501.18 to $553.17 kg −1 can be …Web

It's actually thorium oxide ("thoria"), by itself an insulator, that is added to the tungsten. Though it is, in fact, the metallic thorium film, a monolayer adsorbed at the surface, that is responsible for the reduction of the work function. Simply because thorium has a lower work function than tungsten does: 3.4 vs. 4.5 eV. Or put another way…Web

Included in this report are data concerning the strength, density, and porosity that may be expected of thoria ceramics formed by dry-pressing and isostatic pressing and fired at …Web

Thorium Oxide is a highly insoluble thermally stable Thorium source suitable for glass, optic and ceramic applications. Thorium Oxide is …Web

lenses for cameras and scientific instruments. [4]. The phase diagram for thorium and oxygen shows that only one oxide phase is thermodynamically present at ambient pressure: thorium dioxide. [5] ThO2 has one of the highest melting point (3300 °C) of all oxides [6] and thus used in heat-resistant ceramics [3] and in mantles of portable gas lights.Web

The thorium fuel is in the form of pellets composed of a dense thorium oxide ceramic matrix containing about 10% of finely blended plutonium oxide as a 'fissile driver'. As a mixed-oxide (MOX) fuel variant it is familiar to the nuclear industry, but thorium-MOX fuel has certain advantages compared to the uranium-MOX fuels in use at …Web

The most frequently used metal oxide ceramics are alumina (Al 2 O 3) and zirconia (ZrO 2. ... The presence of uranium and thorium makes zircon deposits radioactive, so care needs to be taken when mining the ore. When milled to very fine powders and then subjected to a process called sintering, both alumina and zirconia are transformed into ...Web

Thorium oxide has the highest temperature of any ceramic, melting at 3300 o K. ... Ultra High Temperature Materials For Lunar Processing Conference Paper Jun …Web

Used in high-temperature ceramics, gas mantles, nuclear fuel, flame spraying, crucibles, non-silicia optical glass, catalysis, filaments in incandescent lamps, cathodes in electron tubes and arc-melting electrodes. Hazards. What is this information? ... Thorium oxide; (Thorium dioxide) () 30 mg/m3 : 330 mg/m3 : 2000 mg/m3Web

Properties of Thorium Oxide Ceramics Properties of Thorium Oxide Ceramics CURTIS, C. E.; JOHNSON, J. R. 00:00:00 Included in this report are data concerning the strength, density, and porosity that may be expected of thoria ceramics formed by dry-pressing and isostatic pressing and fired at 1400°, 1600°,and 1800°C.Web

Here are some key ways in which thorium is utilized in ceramic manufacturing: Thermal Stability: Thorium dioxide (ThO2), also known as thorium oxide, is added to ceramics to increase their thermal stability. Ceramics containing thorium can withstand high temperatures without significant deformation or degradation.Web

The thorium oxide powder was supplied by India Rare E arths . ... times a cored structure is visible in fractured sintered ceramic pellets. Two types of coring have been mentioned .Web