Korea Institute of Geoscience and Mineral Resources

Korea Institute of Geoscience and Mineral Resources (kigam)

Commonwealth Scientific and Industrial Research Organisation

Han Kwon Chang

Hee Dong Jang

Dae Sup Kil

Kuk Cho

Kok Seng Lim

Sung-Wook Cho

Jonian Nikolov

Jiwoong Kim

Disclosed is a method for selectively separating and recovering silicon from waste silicon sludge generated during a semiconductor manufacturing process. With the method for separating and recovering silicon from the silicon sludge, oil components, iron, silicon carbide that are included in the silicon sludge may be removed and silicon may be selectively separated and recovered. In addition, silicon may be efficiently recovered without injection of an additive for precipitating a specific component or without a separate device such as a magnetic separator, or the like, for removing iron.

Method for separating and recovering silicon from silicon sludge

Disclosed is a method of preparing mesoporous silica particles. The method includes (a) preparing an aqueous silicic acid, (b) spraying the aqueous silicic acid in a droplet state by activating the aqueous silicic acid, and (c) pyrolyzing the sprayed droplet through a reactor, which is previously heated, by allowing the sprayed droplet to pass through the reactor together with a carrier gas. The aqueous silicic acid includes 0.4 M to 0.8 M of silicic acid.

Method of preparing mesoporous silica particles using spray pyrolysis

The present invention provides a method for preparing nanoporous Pt/TiOcomposite particles, nanoporous Pt/TiOcomposite particles prepared by the above preparation method, and a fuel cell comprising the nanoporous Pt/TiOcomposite particles. The nanoporous Pt/TiOcomposite particles according to the present invention have a catalytic effect similar to that of commercially available Pt/carbon black and, thus, can be applied to a fuel cell.

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A droplet generation system includes a first nozzle configuration structured to receive a liquid and a gas under pressure in a controllable feed ratio, and to merge the liquid and gas to form an intermediate stream that is a mixture of the gas and of a dispersed phase of the liquid. A second nozzle configuration is connected to receive the intermediate stream from the first nozzle configuration and has a valve mechanism with one or more controllable operating parameters to emit a stream of droplets of the liquid. The mean size of the droplets is dependent on the controllable feed ratio of the liquid and gas and the flow rate of the stream of droplets is dependent on the controllable operating parameter(s) of the valve mechanism. A corresponding method is disclosed, as is the application of the system and method to the production of nanoparticles in a thermochemical reactor.

Droplet generation system and method

Disclosed is a method of synthesizing hollow silica having the size of micrometers from sodium silicate. The method includes fabricating a polystyrene organic template from polystyrene latex, (B) cleaning the polystyrene organic template, (C) exchanging media by using a water-base medium, introducing the cleaned polystyrene organic template and sodium silicate, and preparing a silica-coated organic template by performing an acidic hydrolysis reaction, and (D) cleaning the silica-coated organic template included in the water-base medium by using water. The size of the organic template is adjusted by controlling an amount of introduced AIBN included when the organic template is fabricated. The cleaning of the organic template is preferably performed by using water (HO). The method further includes (B) removing the organic template by using THF and (F) cleaning the hollow silica having no organic template.

Method of synthesizing hollow silica from sodium silicate

Disclosed is a method for producing a cerium dioxide nanopowder by flame spray pyrolysis. The method comprises dissolving a cerium compound in an organic solvent to prepare a precursor solution, atomizing the precursor solution into microdroplets using an ultrasonic atomizer, transferring the microdroplets together with an argon gas as a carrier gas to a central portion of a high-temperature diffusion flame burner, subjecting the microdroplets to pyrolysis and oxidation in the central portion of the diffusion flame burner to produce a cerium dioxide nanopowder, and collecting the cerium dioxide nanopowder using a collector. According to the method, a cerium dioxide nanopowder can be continuously produced on a large scale by flame spray pyrolysis. In addition, the particle size and uniformity of the cerium dioxide nanopowder can be controlled by appropriately selecting the kind of the solvent and the concentration of the raw material. Furthermore, flame spray pyrolysis allows the cerium dioxide to have a fluorite crystal structure.

Method for producing cerium dioxide nanopowder by flame spray pyrolysis and cerium dioxide nanopowder produced by the method

Provided is a method of fabricating silica-titania nanoporous composite powder by controlling a pore size. In more particular, a method of fabricating silica-titania nanoporous composite powder, using a spraying and heating reactor including an ultrasonic droplet generator and a cylindrical electric furnace, comprises the steps of: generating droplets of a mixture suspension from a colloidal suspension prepared by mixing silica (SiO) and titania (TiO) nanopowders and organic template (PSL: polystyrene latex) powder, by the ultrasonic droplet generator of the spray-heating reactor; generating a silica-titania-organic template nanoporous composite powder having pores within the range of 20&#x2dc;100 nm in size through preparing silica-titania-organic template (SiO&#x2014;TiO-PLS) composite particles and removing the organic template while passing the mixture suspension in the cylindrical electric furnace by a carrier gas; and collecting the generated nanoporous material by a particle collector.

Method of fabricating silica-titania nanoporous composite powder

The invention relates to a method for making silica nanoparticles using a flame reactor, which includes a droplet spray having a two-fluid nozzle and a burner of a quintuple tube structure. In this method, droplets of silicon alkoxide as liquid Si compound are sprayed through the droplet spray of the flame reactor. A flame is generated by the flow of inert gas, oxygen, hydrogen and air simultaneously into the burner of the flame reactor. The liquid Si compound is delivered through the flame of the burner to produce silica nanoparticles having a mean particle size ranging from 9 nm to 68 nm. Resultant nanoparticles are collected and recovered in a particle collector. The droplets sprayed under high pressure from a silicon alkoxide solution are directly oxidized in the flame, thereby producing spherical silica nanoparticles.

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Daejeon, South Korea

Han Kwon Chang