摘要:
Disclosed are metal oxide having high thermal stability and a preparation method thereof, specifically including continuously reacting a reaction mixture, composed of (i) water, (ii) a first metal salt including an aqueous cerium compound and (iii) a second metal salt including an aqueous aluminum compound, at 200~700 °C under pressure of 180-550 bar, the reaction product having a molar ratio of metal, other than aluminum, to aluminum of 0.1~10.
摘要:
A purification method is disclosed for a predetermined water-insoluble extractant present in a liquid phase composition that additionally contains one or more additional extractants, synthesis reaction starting materials, and reaction byproducts dissolved as solutes in an organic diluent. An ion-containing compound is admixed with the composition to form an extractant/ion complex in the organic diluent phase that has an affinity for a new phase that is greater than the affinity for the first-named phase. The predetermined extractant/ion complex is separated from the diluent by using the new phase affinity, and the extractant/ion complex is preferably although not necessarily recovered. The extractant/ion complex is separated into extractant and ion. The extractant is recovered. Exemplary extractants include polyethers, crown ethers, crown thioethers, calixarenes, polyamines, cryptands, porphyrins and the like.
摘要:
A ?99Mo/99m¿Tc generator system includes a sorbent column (11) loaded with a composition containing 99Mo. The sorbent column (11) has an effluent end (31) in fluid communication with an anion-exchange column (15) for concentrating 99mTc eluted from the sorbent column (11). A method of preparing a concentrated solution of 99mTc includes the general steps of a) providing a sorbent column (11) loaded with a composition containing 99Mo, the sorbent column having an effluent end (31) in fluid communication with an anion-exchange column (15); b) eluting the sorbent column (11) with a salt solution to elute 99mTc from the sorbent and to trap and concentrate the eluted 99mTc on the anion-exchange column; and c) eluting the concentrated 99mTc from the anion-exchange column with a solution comprising a reductive complexing agent.
摘要:
A unique crystalline bis-ammonia metal molybdate material has been developed. The material may be used as a hydroprocessing catalyst. The hydroprocessing may include hydrodenitrification, hydrodesulfurization, hydrodemetallation, hydrodearomatization, hydrodesilication, hydroisomerization, hydrotreating, hydrofining, and hydrocracking.
摘要:
A high radiation resistant inorganic sorbent is used for the extraction of Mo-99 from the fission byproducts of a uranyl sulfate nuclear-fueled homogeneous-solution nuclear reactor. The sorbent is a composition of hydrated titanium dioxide combined with 5 to 40 mole percent zirconium hydroxide formed into pellets and saturated with an isotope composition of uranium.
摘要:
Dans un système de chauffe-eau, la vapeur contenue dans les produits des gaz de combustion est condensée dans un échangeur thermique secondaire (22) positionné dans une enceinte avec l'échangeur thermique primaire (20) et la chambre de combustion (44). Les deux échangeurs thermiques sont constitués par des enroulements coaxiaux, l'enroulement secondaire entourant le primaire. Les gaz s'écoulent radialement au travers de l'enroulement primaire, axialement le long d'un déflecteur (46) et ensuite axialement au travers de l'enroulement secondaire à une vitesse accrue. Le mélange gaz/air est brûlé dans un brûleur (50) à l'intérieur de l'échangeur thermique primaire et les produits gazeux sont aspirés au travers des échangeurs par une soufflante (58). Un réservoir de stockage d'eau (34) permet d'améliorer la stratification de l'eau chaude sur l'eau plus froide. L'eau plus froide est utilisée pour condenser la vapeur dans l'échangeur thermique secondaire.
摘要:
A method for preparing alpha sources of polonium. A sample of polonium is provided in a solution. A controlled amount of sulfide and a controlled amount of a metal capable of forming an insoluble sulfide salt in the solution are introduced into the solution, in order to co-precipitate polonium from the solution. The precipitates are filtered out.
摘要:
A process for the production of ultrafine powders consisting of individual particles with sizes in the range of 1 nm to 200 nm, which is based on the mechanical milling of two or more non-reacting powders. The process includes subjecting a suitable precursor metal compound and a non-reactant diluent phased to mechanical milling which through the process of mechanical activation reduces the microstructure of the mixture of the form of nano-sized grains of the metal compound uniformly dispersed in the diluent phase. Heat treating the milled powder converts the nano-sized grains of the precursor metal compound into a desired metal oxide phase. Alternatively, the precursor metal compound may itself be an oxide phase which has the requisite milling properties to form nanograins when milled with a diluent. An ultrafine powder is produced by removing the diluent phase such that nano-sized grains of the desired metal oxide phase are left behind. The process facilitates a significant degree of control over the particle size and size distribution of the particles in the ultrafine powder by controlling the parameters of mechanical activation and heat treatment.