Abstract:
There is provided a method and an apparatus for producing metal oxide particles, which produce metal oxide particles having a high photocatalytic activity with high yield. The method for producing metal oxide particles of the invention is characterized by including combining, in a reaction tube, a preheated metal chloride-containing gas with a preheated first gas which does not contain the metal chloride at a first junction to obtain a first combined gas, and combining the first combined gas with a preheated second gas which does not contain the metal chloride, at a second junction which is further downstream of the first junction, to obtain a second combined gas, wherein at least one of the metal chloride-containing gas and the first gas contains oxygen, and wherein the preheated metal chloride-containing gas is further heated in a region between the first junction and the second junction (referred to as first reaction zone), by combining the first gas with the metal chloride-containing gas at the first junction while setting the preheat temperature of the first gas at a temperature equal to or higher than the preheat temperature of the metal chloride-containing gas, and the first combined gas is further heated in a region downstream of the second junction by combining the second gas with the first combined gas at the second junction while setting the preheat temperature of the second gas at a temperature equal to or higher than the temperature of the first combined gas.
Abstract:
The present invention relates to a preparation method of metal oxide, and more specifically to a preparation method of metal oxide comprising the steps of : a) dissolving metal halide in a solvent; b) adding and reacting water or metal hydroxide having strong basicity; c) adding base to the reaction solution and then raising a temperature thereof to form the metal oxide -carbon complex; d) stopping the reaction by inputting a large amount of water or metal hydroxide and raising the temperature thereof; and e) obtaining the metal oxide-carbon complex by a separation and a cleaning.
Abstract:
There is provided a method and an apparatus for producing metal oxide particles, which produce metal oxide particles having a high photocatalytic activity with high yield. The method for producing metal oxide particles of the invention is characterized by including combining, in a reaction tube, a preheated metal chloride-containing gas with a preheated first gas which does not contain the metal chloride at a first junction to obtain a first combined gas, and combining the first combined gas with a preheated second gas which does not contain the metal chloride, at a second junction which is further downstream of the first junction, to obtain a second combined gas, wherein at least one of the metal chloride-containing gas and the first gas contains oxygen, and wherein the preheated metal chloride-containing gas is further heated in a region between the first junction and the second junction (referred to as first reaction zone), by combining the first gas with the metal chloride-containing gas at the first junction while setting the preheat temperature of the first gas at a temperature equal to or higher than the preheat temperature of the metal chloride-containing gas, and the first combined gas is further heated in a region downstream of the second junction by combining the second gas with the first combined gas at the second junction while setting the preheat temperature of the second gas at a temperature equal to or higher than the temperature of the first combined gas.
Abstract:
A process and apparatus for the synthesis of metal oxide nanopowder from a metal compound vapour is presented. In particular a process and apparatus for the synthesis of Ti02 nanopowder from TiCl4 is disclosed. The metal compound vapour is reacted with an oxidizing gas in electrically induced RF frequency plasma thus forming a metal oxide vapour. The metal oxide vapour is rapidly cooled using a highly turbulent gas quench zone which quickly halts the particle growth process, yielding a substantial reduction in the size of metal oxide particles formed compared with known processes. The metal compound vapour can also react with a doping agent to create a doped metal oxide nanopowder. Additionally, a process and apparatus for the inline synthesis of a coated metal oxide is disclosed wherein the metal oxide particles are coated with a surface agent after being cooled in a highly turbulent gas quench zone.
Abstract:
The present invention relates to a preparation method of metal oxide, and more specifically to a preparation method of metal oxide comprising the steps of : a) dissolving metal halide in a solvent; b) adding and reacting water or metal hydroxide having strong basicity; c) adding base to the reaction solution and then raising a temperature thereof to form the metal oxide -carbon complex; d) stopping the reaction by inputting a large amount of water or metal hydroxide and raising the temperature thereof; and e) obtaining the metal oxide-carbon complex by a separation and a cleaning.
Abstract:
This disclosure relates to a process for producing titanium dioxide, comprising: a) providing a quantity of liquid titanium tetrahalide for reacting with an oxygen-containing gas; b) vaporizing a first portion of the liquid titanium tetrahalide and reacting the titanium tetrahalide vapor and the oxygen-containing gas, in a first stage of a reaction zone, the reaction zone temperature ranging from at least about 650°C to form a reaction product at least containing titanium dioxide and oxygen-containing gas and passing the reaction product, more typically in the vapor phase, to at least one additional stage of the reaction zone; and c) charging at least one additional portion of the liquid titanium tetrahalide to the at least one additional stage of the reaction zone to cool the titanium dioxide and to react with the oxygen-containing gas to form additional titanium dioxide. This process results in a high conversion to titanium dioxide and formation of titanium dioxide powders having improved particle size and size distribution.
Abstract:
The present invention provides a method for varying and controlling the chemical composition and physical properties of the uranium oxide solids produced by the thermal conversion of UF6. The method allows the production of predominantly UO2, U3O8, or UO3 interchangeably from the same reactor simply by controlling the hydrogen and oxygen contents of the feed relative to uranium. The temperature profile of the thermal reactor is established by specifying the preheat of the feed prior to mixing, the feed composition, and the reactor wall temperature to thus vary and control the physical properties of the resulting solids according to the end use of the uranium product.
Abstract:
A method for generating chlorine dioxide is disclosed in which chlorine dioxide generation is activated with a dry polar material. A system for generating chlorine dioxide is also disclosed, as well as compositions useful in the system and method.