Abstract: The present invention relates to a method of extracting lithium with high purity from a lithium bearing solution by electrolysis. More specifically, the present invention provides a method of economical extraction of lithium from the lithium bearing solution by adding a phosphorous supplying material to the solution to prepare a lithium phosphate aqueous solution subject to electrolysis.

Abstract: A steel frame structure includes brackets connected to columns to allow the columns to be connected to a girder. Each bracket includes a U-shaped plate having a bottom plate, side plates extended upwardly perpendicularly from both ends of the bottom plate, and base plates extended outwardly from the side plates, a vertical plate welded perpendicularly to the center of the bottom plate of the U-shaped plate in such a manner as to be parallel to the side plates, and a horizontal plate welded to the top end of the vertical plate in such a manner as to be parallel to the bottom plate of the U-shaped plate. The girder has a generally U-shaped section.

Abstract: A method of connecting a steel pipe pile and a steel pipe column using a steel pipe socket according to the present invention may include: preparing the steel pipe socket including a socket supporting portion which covers an upper end surface of the steel pipe pile; inserting a plurality of socket insertion portions which are extended downward from the socket supporting portion, and have a plurality of socket grooves at a lower end portion thereof and a plurality of fastening members which are installed on the socket supporting portion; inserting the socket grooves of the steel pipe socket into an upper end portion of the steel pipe pile; mounting the steel pipe column on the socket supporting portion; and fastening the steel pipe column and the steel pipe pile using the plurality of fastening members of the socket supporting portion

Abstract: Methods of manufacturing Fe and Ni-containing material and Co-containing material from petrochemical desulfurization residue containing Fe and Ni or Fe and Co, manufacturing raw material for stainless steel using the Fe and Ni-containing material, and manufacturing ferro-nickel using the Fe and Ni-containing material. The method of manufacturing Ni and Fe-containing material includes acid-treating Ni and Fe-containing residue to remove alkali therefrom; drying the residue and heat treating the residue in a temperature range from 600° C. (degree Centigrade) to 1300° C.

Abstract: The present invention relates to a method of economical extraction of magnesium, boron and calcium, while minimizing the loss of lithium, from a lithium bearing solution. More specifically, the present invention provides a method for economical extraction of magnesium, boron, and calcium, while minimizing the loss of lithium, from a lithium bearing solution comprising the steps of: (a) adding an alkali in the lithium bearing solution to precipitate magnesium hydroxide; (b) absorbing boron ions on the surface of the magnesium hydroxide by adjusting the pH to about 8.5 to about 10.5; and (c) simultaneously extracting magnesium and boron by filtering the magnesium hydroxide absorbed with the boron ions from the lithium bearing solution.

Abstract: The present invention relates to a method for producing biodiesel comprising a step of generating fatty acid alkyl ester and glycerol by a transesterification of animal and vegetable oils and fats and fatty acid alcohols in the presence of porous materials. The method is characterized by a high response speed and high FAME conversion, and can be performed in a consecutive process. Further, according to the method, a high-purity fatty acid alkyl ester and glycol can be produced irrespective of the content of free fatty acids (FFAs). Further, since the method does not use a catalyst, the total processing time and cost can be reduced, and the method is environmentally friendly.

Abstract: The present invention relates to a method of extracting lithium from a lithium bearing solution. More specifically, the present invention provides a method of economical extraction of lithium from a lithium bearing solution by adding a phosphorous supplying material to the solution to precipitate lithium phosphate from the dissolved lithium.

Abstract: The present invention provides a method for preparing dialkyl carbonate from urea or alkyl carbamate and alkyl alcohol using an ionic liquid comprising a cation, which produces a hydrogen ion, and a hydrophobic anion containing fluorine with high temperature stability in the presence of catalyst containing a metal oxide or hydrotalcite. Since the present invention can prepare dialkyl carbonate at a pressure lower than those of existing methods, it does not require an expensive pressure control device and peripheral devices for maintaining high pressure including the installation cost. It is also the method for preparing a dialkyl carbonate with high yield, thus improving economical efficiency. Moreover, the method of the present invention hardly produces any waste during the process and is thus an eco-friendly method.

Abstract: Disclosed is a method for preparing a dialkyl carbonate, in which a dialkyl carbonate such as dimethyl carbonate is economically prepared in an environmentally-friendly manner at a higher yield while reducing generation of a by-product. The method for preparing the dialkyl carbonate includes reacting urea, an alkyl carbamate having 1 to 3 carbon atoms, or a mixture thereof with a monovalent alcohol having 1 to 3 carbon atoms in the presence of a room temperature ionic liquid and a catalyst including a salt of a transition metal or a rare earth metal.

Abstract: The present invention provides a method for preparing dialkyl carbonate from urea or alkyl carbamate and alkyl alcohol using an ionic liquid comprising a cation, which produces a hydrogen ion, and a hydrophobic anion containing fluorine with high temperature stability in the presence of catalyst containing a metal oxide or hydrotalcite. Since the present invention can prepare dialkyl carbonate at a pressure lower than those of existing methods, it does not require an expensive pressure control device and peripheral devices for maintaining high pressure including the installation cost. It is also the method for preparing a dialkyl carbonate with high yield, thus improving economical efficiency. Moreover, the method of the present invention hardly produces any waste during the process and is thus an eco-friendly method.

Abstract: The present invention relates to hard coating layer and a method for forming the hard coating layer. A method for forming hard coating layer which comprises: washing a substrate; installing the washed substrate in a vacuum equipment, and vacuating the chamber of the vacuum equipment; cleaning the substrate; forming oblique coating layer on the substrate; and forming vertical coating layer, vertically to the substrate, on the oblique coating layer by applying bias-voltage after forming oblique coating layer is provided. According to present invention, hardness of coating layer may be enhanced by forming a oblique coating layer and vertical coating layer on a substrate.

Abstract: In the method for welding a hollow structure of the present invention, a rib is placed between a first joining member and a second joining member, and friction stir welding and fixing a place where the rib is placed between the first and the second joining member are conducted. Thus, friction stir welding is accomplished without changing the shape of an extrusion part or partly changing the shape of the extrusion part with insertion of a simply shaped rib.

Abstract: A method of manufacturing an Fe/Ni-containing material having a low content of sulfur from an Fe/Ni/SO4-containing liquid waste, a ferronickel mass using the Fe/Ni-containing material, and a method of manufacturing the ferronickel mass. The method includes: removing SO4 from an Fe/Ni/SO4-containing liquid waste by adding an SO4 neutralizing agent to the liquid waste so that pH of the liquid waste can be maintained to a pH level of 0.5 to 2.5; precipitating Fe and Ni in the form of hydroxide [(Ni,Fe)(OH)] by adding NaOH to the SO4-free solution; washing the precipitate with water; and manufacturing an Ni/Fe-containing material by filtering and drying the washed Ni/Fe-containing sludge. The method may be useful to suitably apply to the field of recycling of waste acids since an Fe/Ni-containing pellet and a high purity plaster are recovered as the stainless steel material from the waste water at the same time.

Abstract: A method of manufacturing iron-based powder includes providing an iron-based molten steel manufactured through a iron making process and a steelmaking process to a tundish; and performing water atomization over the molten steel discharged through a nozzle connected to the tundish. The iron-based powder is manufactured from the molten steel refined after a molten iron tapped from a iron making process is charged into a converter without a pre-treatment process of the molten iron, thus economically providing the highly clean iron-based powder.

Abstract: The present invention relates to hard coating layer and a method for forming the hard coating layer. A method for forming hard coating layer which comprises: washing a substrate; installing the washed substrate in a vacuum equipment, and vacuating the chamber of the vacuum equipment; cleaning the substrate; forming oblique coating layer on the substrate; and forming vertical coating layer, vertically to the substrate, on the oblique coating layer by applying bias-voltage after forming oblique coating layer is provided. According to present invention, hardness of coating layer may be enhanced by forming a oblique coating layer and vertical coating layer on a substrate.

Abstract: The present invention relates to a method of preparing olivine cathode materials for lithium secondary battery. More specifically, a method of preparing an olivine-based cathode material for secondary battery comprising the steps of: dissolving an iron supplying material, and a lithium phosphate by adding an acid; forming a chelate polymer by adding a chelate agent and a polymerization agent in the solution of the dissolving step followed by heating; pyrolyzing the chelate polymer under reducing atmosphere; and thermally reducing the chelated polymer degraded during the pyrolysis is provided.

Abstract: The present invention relates to a method of extracting lithium with high purity from a lithium bearing solution by electrolysis. More specifically, the present invention provides a method of economical extraction of lithium from the lithium bearing solution by adding a phosphorous supplying material to the solution to prepare a lithium phosphate aqueous solution subject to electrolysis.

Abstract: The present invention relates to a method of extracting lithium from a lithium bearing solution. More specifically, the present invention provides a method of economical extraction of lithium from a lithium bearing solution by adding a phosphorous supplying material to the solution to precipitate lithium phosphate from the dissolved lithium.

Abstract: The present invention relates to a method of economical extraction of magnesium, boron and calcium, while minimizing the loss of lithium, from a lithium bearing solution. More specifically, the present invention provides a method for economical extraction of magnesium, boron, and calcium, while minimizing the loss of lithium, from a lithium bearing solution comprising the steps of: (a) adding an alkali in the lithium bearing solution to precipitate magnesium hydroxide; (b) absorbing boron ions on the surface of the magnesium hydroxide by adjusting the pH to about 8.5 to about 10.5; and (c) simultaneously extracting magnesium and boron by filtering the magnesium hydroxide absorbed with the boron ions from the lithium bearing solution.

Abstract: There are provided a landmark for recognizing a position of a mobile robot moving in an indoor space and an apparatus and method for recognizing the position of the mobile robot by using the landmark. The landmark includes a position recognition part formed of a mark in any position and at least two marks on an X axis and Y axis centered on the mark and further includes an area recognition part formed of a combination of a plurality of marks to distinguish an individual landmark from others. The apparatus may obtain an image of the landmark by an infrared camera, detect the marks forming the landmark, and detect precise position and area information of the mobile robot from the marks.