Thorium powder

Thiourea, mercury(II) chloride complexes with, 6 26 Thorium, powder by reduction of oxide with calcium, 6 50 removal of, in extraction of... 

Derivation (1) Reduction of thorium dioxide with calcium (2) fused salt electrolysis of the double fluoride ThF4 KF. The product of both processes is thorium powder, fabricated into the metal by powder metallurgy techniques. Hot surface decomposition of the iodide produces crystal bar thorium. 

F2. Fuhrman, N., et al. The Production of Thorium Powder by Calcium Reduction of Thorium Oxide, Report SCNC-185, 1957. 

Small, relatively compact cylinders are formed from thorium powder under a pressure of 6-7 tons/cm . Crucibles of sintered thoria are suitable melt containers. The cylinder, wrapped in a tungsten wire spiral, is placed inside such a crucible which is set up in a quartz container connected to a high-vacuum pump. The material is heated with a high-frequency induction coil. 

Thorium powder with a completely clean surface is noteworthy for its sensitivity to air after high-vacuum degassing at 400°C. This sensitivity is so pronounced that the metal catches fire on coming in contact with air. The material also reacts so vigorously with Hg that it becomes red hot. 

Thorium powder may be prepared from the solid via the hydride. The procedure is identical to that described on p. 1170 for Ti and Zr the hydride should be decomposed above 700°C. 

Judge, E.L., Barefield, J.E., Berg, J.M. et al. (2013). Laser-induced breakdown spectroscopy measurements of uranium and thorium powders and uranium ore, Spectrochim. Acta B 83-84, 28-36. 

If thorium powder is added to the li( uid bismuth surface at the reaction temperature, it is necessary to stir the thorium into the liquid. Otherwdse a crust of intermetallic compound forms on the surface which is rigid enough to support suV)seqiient additions, thus preventing contact between the thorium and the bismuth. 

For the production of lamp-filament wire, aluminum, potassium, and siHcon dopants are added to the blue oxide. Some dopants are trapped in the tungsten particles upon reduction. Excess dopants are then removed by washing the powder in hydroflouric acid. Eor welding electrodes and some other appHcations, thorium nitrate is added to the blue oxide. After reduction, the thorium is present as a finely dispersed thorium oxide. 

Carbides of the Actinides, Uranium, and Thorium. The carbides of uranium and thorium are used as nuclear fuels and breeder materials for gas-cooled, graphite-moderated reactors (see Nuclearreactors). The actinide carbides are prepared by the reaction of metal or metal hydride powders with carbon or preferably by the reduction of the oxides uranium dioxide [1344-57-6] UO2 tduranium octaoxide [1344-59-8], U Og, or thorium... 

In a chemical vapor deposition (CVD) variant of conventional powder metallurgy processing, fine chromium powder is obtained by hydrogen reduction of Crl2 and simultaneously combined with fine thorium(IV) oxide [1314-20-17, H1O2, particles. This product is isostaticaHy hot pressed to 70 MPa (700 atm) and 1100°C for 2 h. Compacts are steel clad and hot roUed to sheets (24). 

Boron phases with formulas MB50, and MB,00 (M = Y, Sm, Gd, Tb, Dy, Ho, Er, Yb, Tm, Lu, Th and Pu) are the same cubic phase from x-ray powder data , with the Fm3c Sjpace group. Single crystals of yttrium and thorium borides lead to the formula The MB lattice constant data are given in Table 1. 

Several incidents in which moisture has contributed to fires or explosions, in some of which water was definitely the sole oxidant, in zirconium, magnesium, uranium and thorium scraps or powders are retailed, largely sourced from an earlier paper. However, a plutonium fire was extinguished with water. 

Hartmann, I. et al., Rept. Invest. No. 4835, Washington, US Bur. Mines, 1951 Thorium hydride explodes on heating in air [1], and the powdered hydride readily ignites on handling in air [2], Layers of thorium or uranium hydrides ignited spontaneously after exposure to ambient air for a few min [3],... 

Many furnace residues (fine powders and salts) deposited in the upper parts of furnaces used for thorium melting operations, are highly pyrophoric and often ignite as the furnace is opened. Such residues may be rendered safe by storage under water for 60-90 days. If the water is drained off early, ignition may occur. 

Following the characterization of U(COT)2, the analogous thorium complex was synthesized 12). Its physical and chemical properties were so different from those of the uranium compound that initially there was question as to whether the complex had the same -sandwich structure. The X-ray structure anal5 is however showed it to be isostructural with U(COT)2 11). Subsequently, Pu(COT)2 13), Np(COT) 13), and Pa(COT)2 14, 15) have been prepared and their X-ray powder patterns show them all to be isostructural with U(COT)2. 

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