화학공학소재연구정보센터
홈 로그인 로그아웃 연락처 사이트맵
Korean Journal of Materials Research, Vol.22, No.11, 620-625, November, 2012
DOI10.3740/MRSK.2012.22.11.620  Export Citation
FeC2O4·2H2O의 열처리 조건이 Fe3O4-δ 형성에 미치는 영향
Effects of Heat Treatment Conditions of FeC2O4·2H2O on the Formation of Fe3O4-δ
오경환1, 박원식1, 2, 이상인3, 서동수1, †
  • 1충남대학교 재료공학과
  • 2한전전력연구원
  • 3대덕대학교 기계설계과
Kyoung-Hwan Oh1, Won-Shik Park1, 2, Sang-In Rhee3, and Dong-Soo Suhr1, †
  • 1Department of Materials Science and Engineering, Chungnam National University, Daejeon 305-764, Korea
  • 2KEPRI, Daejeon 305-760, Korea
  • 3Dept. of Mechanical Design, Daeduk College, Daejeon 305-715, Korea
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A general synthetic method to make Fe3O4-δ (activated magnetite) is the reduction of Fe3O4 by H2 atmosphere. However, this process has an explosion risk. Therefore, we studied the process of synthesis of Fe3O4-δ depending on heattreatment conditions using FeC2O4·2H2O in Ar atmosphere. The thermal decomposition characteristics of FeC2O4·2H2O and the δ-value of Fe3O4-δ were analyzed with TG/DTA in Ar atmosphere. β-FeC2O4·2H2O was synthesized by precipitation method using FeSO4·7H2O and (NH4)2C2O4·H2O. The concentration of the solution was 0.1 M and the equivalent ratio was 1.0. β- FeC2O4·2H2O was decomposed to H2O and FeC2O4 from 150oC to 200oC. FeC2O4 was decomposed to CO, CO2, and Fe3O4 from 200oC to 250oC. Single phase Fe3O4 was formed by the decomposition of β-FeC2O4·2H2O in Ar atmosphere. However, Fe3C, Fe and Fe4N were formed as minor phases when β-FeC2O4·2H2O was decomposed in N2 atmosphere. Then, Fe3O4 was reduced to Fe3O4-δ by decomposion of CO. The reduction of Fe3O4 to Fe3O4-δ progressed from 320oC to 400oC; the reaction was exothermic. The degree of exothermal reaction was varied with heat treatment temperature, heating rate, Ar flow rate, and holding time. The δ-value of Fe3O4-δ was greatly influenced by the heat treatment temperature and the heating rate. However, Ar flow rate and holding time had a minor effect on δ-value.
Keywords:iron oxalate dihydrate;activated magnetite;non-explosive process;δ-value;CO2 decomposition
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