121st General Meeting of the KCS

Type Poster Presentation
Area Inorganic Chemistry
Room No. Event Hall
Time 4월 19일 (목요일) 11:00~12:30
Code INOR.P-106
Subject Simple Synthesis of MgCO3 and Na2Mg(CO3)2 through Alkali Metal Nitrate Medium
Authors Kyung-Ryul Oh, Kang Yeong Kim, Jin-Su Kwak, Young-Uk Kwon*
Department of Chemistry, Sungkyunkwan University, Korea
Abstract MgCO3 and Na2Mg(CO3)2 are anhydrous forms of magnesium carbonate, which are hard to synthesize in aqueous solution at ambient temperature and pressure because of large hydration energy of magnesium ion. Molten salt provides liquid medium at higher temperature than normal solvents, therefore various kinds of metal oxides have been synthesized by molten salt method. Furthermore, alkali metal nitrates are used as promoting agents for MgO-based CO2 absorbent at intermediate temperature (200-500 °C). Based on these backgrounds, we successfully synthesized anhydrous MgCO3 and Na2Mg(CO3)2 using hydromagnesite (MCH) and alkali metal nitrate at 325 °C under CO2 flow. Water of hydration decomposes and Mg(OH)2 converts into MgCO3 at given condition. The existence of Na2CO3 determines the products being MgCO3 or Na2Mg(CO3)2. It was confirmed that neither of MCH nor a mixture of MCH and Na2CO3 produces MgCO3 or Na2Mg(CO3)2 at same condition. Every kind of alkali metal nitrate successfully acted as a reaction medium, giving different particle morphology. The characterization of samples were performed by powder X-ray diffraction measurements (XRD), thermogravimetric analyzer (TGA), and field emission scanning electron microscopy (FE-SEM), which verified that the synthesized products are pure anhydrous rhombohedral MgCO3 and Na2Mg(CO3)2.
E-mail ohkyung1129@naver.com