摘要:
An object of the present invention is to provide a method for producing metal oxide particles, in which metal oxide particles with high photocatalytic activity is produced, and a production apparatus therefor. The above object can be achieved by using a method for producing metal oxide particles, which includes subjecting a reaction gas containing metal chloride and an oxidizing gas containing no metal chloride in a reaction tube (11) to preheating, and then subjecting a combined gas composed of the reaction gas and the oxidizing gas to main heating in a main heating region (A) apart from the downstream side of the junction (5b), wherein the time until the combined gas from the junction (5b) arrives at the upstream end (A1) of the main heating region (A) is adjusted to be less than 25 milliseconds.
摘要:
A gaseous reactant supply apparatus for turning high flow rates of gaseous supply approximately 90 degrees and providing a uniform distribution of gaseous supply. The gaseous supply passes through a venturi throat. Straightening vanes can be positioned inside the venturi throat to reduce rotational motion the gaseous reactant supply may have upon entering the venturi throat. The gaseous reactant supply apparatus exhibits lower pressure drops than exhibited by apparatus of the prior art.
摘要:
Iron oxide-silicon dioxide-titanium dioxide mixed oxide is produced by burning vaporizable compounds of iron, silicon and titanium together in a hydrogen/oxygen flame. The mixed oxides may be used as UV absorbers in cosmetics.
摘要:
Iron oxide-silicon dioxide-titanium dioxide mixed oxide is produced by burning vapourable compounds of iron, silicon and titanium together in a hydrogen/oxygen flame. They are used as UV absorbers in cosmetics.
摘要:
A process for producing an ultrafine mixed-crystal oxide characterized by producing an ultrafine mixed crystal oxide comprising primary particles in a mixed crystal state with a BET specific surface area of 10 to 200 m2/g, comprising the step of subjecting a halogenated metal to high temperature oxidation with an oxidizing gas to produce a metal oxide by a vapor phase production method, wherein said halogenated metal is in the form of a mixed gas (a mixed halogenated metal gas) comprising at least two compounds having a different metal elements selected from the group consisting of chlorides, bromides, and iodides of titanium, silicon, and aluminum, and said mixed halogenated metal gas and said oxidizing gas are independently preheated to 500null C. or more prior to a reaction, a ultrafine mixed crystal oxide obtained by the process, and use of the oxide.
摘要:
The present invention relates to a process for the preparation of finely divided metal and/or ceramic powders by reacting appropriate metal compounds and appropriate reagents in the gas phase (CVR) chemical vapor reaction, wherein the metal compound(s) and the further reagents are brought to reaction in the gaseous state in a reactor and are subsequently homogeneously condensed directly out of the gas phase, with exclusion of any wall reaction, and are subsequently separated from the reaction medium.
摘要:
A low temperature process is described for forming a coating or powder comprising one or more metals or metal compounds by first reacting one or more metal reactants with a halide-containing reactant to form one or more reactive intermediates capable of reacting, disproportionating, or decomposing to form a coating or powder comprising the one or more metal reactants. When one or more metal compounds are formed, either as powders or as coatings, a third reactant may be injected into a second reaction zone in the reactor to contact the one or more reactive intermediates formed in the first reaction zone to thereby form one or more metal compounds such as metal nitrides, carbides, oxides, borides, or mixtures of same.
摘要:
The residual gas obtained in the pyrogenic production of metal oxides or metalloid oxides contain besides the desired product elemental chlorine if a chlorine containing starting material is employed. After cooling the residual gas the elemental chlorine is reacted to form hydrogen chloride by using an aqueous solution of a reducing agent and in this form the chlorine is subsequently washed out of the residual gas.
摘要:
Process for the production of a finely divided oxide of a metal or silicon by the hydrolytic conversion of a volatile corresponding metal halide or silicon halide in a flame, said process comprising feeding the volatile halide in a mixture with a combustible hydrogen-containing gas and air or oxygen to a burner provided with a mouth emitting a flame, burning the mixture in a fire tube to form a first portion of water vapor, said burner surrounded by an annular chamber forming a nozzle through which hydrogen is passed to keep the mouth of the burner free of attachments of solid substances, the quantity of oxygen or air being sufficient for the practically complete combustion of the combustible gas, and the quantities of oxygen or air and combustible gas being sufficient to produce the first portion of water vapor which will at least suffice for the hydrolysis of the volatile halides, and further wherein said flame is allowed to burn in an atmosphere consisting of gases containing a second portion of water vapor, to avoid the formation of halogen gas in waste gases and separating the resulting oxide from other reaction products. The finely divided oxides are useful as additives and fillers in the manufacture of coatings, adhesives and elastomers.
摘要:
Method for producing pigment quality titanium dioxide of controlled particle size by reacting gaseous titanium tetrachloride with an oxygen-containing gas in a reactor having a cylindrical duct, a coaxial cylindrical reaction chamber of diameter greater than the diameter of the duct and spaced below the duct and a frusto-conical divergent duct connecting the cylindrical duct to the reaction chamber, wherein the oxygencontaining gas is introduced through the cylindrical duct and the titanium tetrachloride is introduced into the frusto-conical section of the reactor at a variably selectable location therein.