Korea Institute of Geoscience and Mineral Resources

Northwestern University

Korea Institute of Geoscience and Mineral Resources (kigam)

Commonwealth Scientific and Industrial Research Organisation

Korea Institute of Geoscience and Material Resources

Hee Dong Jang

Han Kwon Chang

Dae Sup Kil

Yong Jae Suh

Kuk Cho

Jiaxing Huang

Myung Eun Ju

Jiayan Luo

Kok Seng Lim

Jae Kyeong Kim

Byoung-Gyu Kim

Sung-Wook Cho

Kee Kahb Koo

Churl Kyoung Lee

Jung Soo Shon

Do Su Kim

Jonian Nikolov

Jiwoong Kim

Han Sang Oh

Capsules comprising crumpled graphene sheets that form a crumpled graphene shell encapsulating an internal cargo comprising nanostructures of a second component are provided. Also provided are anode materials for lithium ion batteries comprising the capsules, wherein the nanostructures are composed of an electrochemically active material, such as silicon.

Crumpled graphene-encapsulated nanostructures and lithium ion battery anodes made therefrom

In one aspect of the present invention, a method of for synthesizing compression- and aggregation-resistant particles includes forming a graphene dispersion solution with micron-sized graphene-based material sheets, nebulizing the graphene dispersion solution to form aerosol droplets, passing the aerosol droplets through a horizontal tube furnace pre-heated at a predetermined temperature by a carrier gas, and drying the aerosol droplets to concentrate and compress the micron-sized graphene-based material sheets into crumpled particles of sub-micron scale.

Crumpled particles, methods of synthesizing same and applications using same

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 removing phosphorus and nitrogen contained in sewage or wastewater using iron ore wastewater. According to the method of the present invention, in which the phosphorus and nitrogen contained in sewage or wastewater are crystallized in the form of struvite using iron ore wastewater containing a large amount of Mgproduced in a process of upgrading low-grade iron ore and removed, it is possible to reduce the cost of Mgand the cost of iron ore wastewater treatment, thereby earning economic profits. Moreover, it is possible to prevent water pollution by the removal of the phosphorus and nitrogen contained in sewage or wastewater. Furthermore, it is possible to use struvite crystals obtained as a by-product as a time-release compound fertilizer so as to reduce the amount of fertilizer used and the number of fertilizations, thereby reducing soil contamination.

Method for removing phosphorus and nitrogen contained in sewage or wastewater using iron ore wastewater

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.

[object Object]

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

The present invention relates to a method for preparing magnetite nanoparticles from low-grade iron ore using solvent extraction and magnetite nanoparticles prepared by the same. According to the method for magnetite nanoparticles from low-grade iron ore of the present invention, it is possible to prepare high-purity magnetite nanoparticles having a purity of 99% or higher by solvent extraction using low-grade iron ore as a starting material, and thus it is possible to reduce the processing cost and the amount of energy used, thus supplying a high-efficiency magnetite nanoparticle adsorbent, which can be industrially applied to wastewater treatment or desalination plant, in large quantities at low cost. In particular, it is possible to effectively treat livestock wastewater, heavy metal wastewater, oil discharged into rivers, etc. at low cost, thus significantly contributing to the prevention of environmental pollution. Moreover, the magnetite nanoparticles prepared by the present invention has a purity of 99.5% and thus can be used as raw materials for high-tech products such as nanoparticle catalysts, magnetic fluids, MRI contrast agents, etc.

Method for preparing magnetite nanoparticles from low-grade iron ore using solvent extraction and magnetite nanoparticles prepared by the same

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

The present invention provides a method for preparing magnetite nanoparticles from low-grade iron ore and magnetite nanoparticles prepared by the same. According to the method of the present invention, in which iron ore leachate is obtained by adding low-grade iron ore powder to an acidic solution, Si and Mg that inhibit the formation of magnetite nanoparticles present in the leachate are selectively removed, iron hydroxide (Fe(OH)) is allowed to be precipitated from a supernatant containing Feions and Feions, a mixed iron solution containing Feions and Feions is prepared using the iron hydroxide (Fe(OH)), and the mixed iron solution is added to an alkaline solution to react, thereby preparing magnetite nanoparticles.

Method for preparing magnetite nanoparticles from low-grade iron ore and magnetite nanoparticles prepared by the same

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 present invention relates to a method for fabricating calcium carbonate nanoparticles dispersed in water from ground calcium carbonate of micrometer (&#x3bc;m) order using beads milling. More particularly, the present invention relates to a method for fabricating calcium carbonate nanoparticles dispersed in water by which a complex aqueous slurry comprising coarse ground calcium carbonate having an average particle size of several micrometers (&#x3bc;m) and a surfactant is subjected to beads milling, such that grinding and dispersion in water of the ground calcium carbonate occur simultaneously, and the resultant calcium carbonate nanoparticles have an average particle size of 10-100 nm and a unimodal clustering distribution.

Fabrication method of CaCO3 nanoparticles using beads milling

The present invention relates to a preparation of iron(II) acetate powder from low grade magnetite and comprises the following steps: (a) adding organic acid to low grade magnetite powder to obtain iron solution; (b) adding hydroxide to the iron solution to obtain iron hydroxide; and (c) adding acetic acid to the iron hydroxide, thereby obtaining iron(II) acetate. According to the present invention, it is possible to obtain high purity iron(II) acetate using low grade magnetite and there are advantages of mass producible environmentally-friendly simple process and prevention of corrosion of facilities.

Preparation of iron(II) acetate powder from a low grade magnetite

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.

Growing community of inventors

Daejeon, South Korea

Hee Dong Jang