Korea Institute of Geoscience and Mineral Resources

Myung Gyu Lee

Young Nam Jang

Kyoung Won Ryu

Seung Woo Lee

Soo-Chun Chae

Young-Nam Jang

Jun Hwan Bang

Kyung Won Ryu

Kyungsun Song

Soo Chun Chae

Kyung Sun Song

Jun-Hwan Bang

Hwanju Jo

Disclosed is a method of detoxifying asbestos of waste slate. The method includes concentrating the asbestos by introducing hydrochloric acid aqueous solution into waste slate powder to dissolve and remove a limestone component contained in the waste slate; and mixing the concentrated asbestos with oxalic acid and performing a low-temperature heat treatment. The waste slate is crushed and pulverized and powder of the crushed and pulverized waste slate is formed in a size in a range of 100 meshes to 300 meshes. The detoxified asbestos includes re-crystallized magnesium oxalate having a rhombohedral or amorphous shape.

Method of detoxifying asbestos contained in waste slate and detoxified asbestos obtained through the same

Provided is a method of synthesizing high-purity calcite capable of controlling a grain size thereof, by reacting an aqueous calcium chloride solution with COgas under strong alkaline condition, to crystallize into white and ultra-fine grain calcite. The method of synthesizing fine-grain calcite according to the present disclosure can decrease super-saturation by producing calcite under the strong alkaline conditions, thereby suppressing generation and growth of grain, resulting in controlling the grain size. Therefore, the above method is useful in producing high-purity ultra-fine grain calcite and can control the grain size of calcite from several hundreds of nanometers to several tens of nanometers by regulating the concentration of an aqueous caustic soda solution.

Method of producing calcite capable of controlling a grain size thereof

Provided is a fixation method of carbon dioxide. The method includes a) grinding waste gypsum to become 200&#x2dc;300 mesh; b) performing reaction by supplying mixed gas while mixing the ground waste gypsum with aqueous ammonia, and c) separating solid from liquid in the manufactured slurry by centrifugation and drying separated solid and liquid portions with calcite and ammonium sulfate, wherein the mixed gas is formed of nitrogen and carbon dioxide, and the carbon dioxide provides carbon dioxide fixation method containing 5&#x2dc;25 wt %. When carbon dioxide is fixed by using waste gypsum, reaction efficiency is remarkably high. The fixation method makes more than 95% of supplied carbon dioxide fixed. Also, provided is an economical method that disposes carbon dioxide as a disposal target without its separation, refinement and liquefaction processes, to thereby remarkably reduce the entire process and costs for processes.

Economical sequestration of carbon dioxide by the mixed gas

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Daejeon, South Korea

Myung Gyu Lee