中国有色金属学报(英文版)
中國有色金屬學報(英文版)
중국유색금속학보(영문판)
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
2014年
10期
3378-3385
,共8页
张湘辉%何川%汪灵%刘菁%邓苗%冯谦
張湘輝%何川%汪靈%劉菁%鄧苗%馮謙
장상휘%하천%왕령%류정%산묘%풍겸
La2(CO3)3·3.4H2O%非等温动力学%同步热分析%脱水反应
La2(CO3)3·3.4H2O%非等溫動力學%同步熱分析%脫水反應
La2(CO3)3·3.4H2O%비등온동역학%동보열분석%탈수반응
La2(CO3)3·3.4H2O%non-isothermal kinetics%simultaneous thermal analysis%dehydration reaction
采用水热法合成单相La2(CO3)3·3.4H2O。采用XRD、FTIR以及DTA-TG对La2(CO3)3·3.4H2O在30~1000°C的热分解过程、中间及最终产物进行表征。在非等温条件下对La2(CO3)3·3.4H2O在30~366°C范围内的热脱水动力学进行研究。采用Flynn-Wall-Ozawa及Friedman 等转化法计算其反应活化能并对其反应阶段进行分析。采用多元非线性回归程序确定其最可能的反应机理及动力学参数。结果表明,La2(CO3)3·3.4H2O 的热脱水为三步竞争反应,一个 n 序列初始反应后为 n 序列竞争反应(FnFnFn 机理)。经最可能的反应机理计算所得的活化能与Friedman等转化法的计算结果非常接近,拟合后的TG及 DTG曲线与原始曲线能较好地吻合。
採用水熱法閤成單相La2(CO3)3·3.4H2O。採用XRD、FTIR以及DTA-TG對La2(CO3)3·3.4H2O在30~1000°C的熱分解過程、中間及最終產物進行錶徵。在非等溫條件下對La2(CO3)3·3.4H2O在30~366°C範圍內的熱脫水動力學進行研究。採用Flynn-Wall-Ozawa及Friedman 等轉化法計算其反應活化能併對其反應階段進行分析。採用多元非線性迴歸程序確定其最可能的反應機理及動力學參數。結果錶明,La2(CO3)3·3.4H2O 的熱脫水為三步競爭反應,一箇 n 序列初始反應後為 n 序列競爭反應(FnFnFn 機理)。經最可能的反應機理計算所得的活化能與Friedman等轉化法的計算結果非常接近,擬閤後的TG及 DTG麯線與原始麯線能較好地吻閤。
채용수열법합성단상La2(CO3)3·3.4H2O。채용XRD、FTIR이급DTA-TG대La2(CO3)3·3.4H2O재30~1000°C적열분해과정、중간급최종산물진행표정。재비등온조건하대La2(CO3)3·3.4H2O재30~366°C범위내적열탈수동역학진행연구。채용Flynn-Wall-Ozawa급Friedman 등전화법계산기반응활화능병대기반응계단진행분석。채용다원비선성회귀정서학정기최가능적반응궤리급동역학삼수。결과표명,La2(CO3)3·3.4H2O 적열탈수위삼보경쟁반응,일개 n 서렬초시반응후위 n 서렬경쟁반응(FnFnFn 궤리)。경최가능적반응궤리계산소득적활화능여Friedman등전화법적계산결과비상접근,의합후적TG급 DTG곡선여원시곡선능교호지문합。
The single phase La2(CO3)3·3.4H2O was synthesized by hydrothermal method. The thermal decomposition and intermediates and final solid products of La2(CO3)3·3.4H2O from 30 to 1000 °C were characterized by XRD, FTIR and DTA-TG. The kinetics of dehydration of La2(CO3)3·3.4H2O in the temperature range of 30-366 °C was investigated under non-isothermal conditions. Flynn-Wall-Ozawa and Friedman isoconversion methods were used to calculate the activation energy and analyze the reaction steps; multivariate non-linear regression program was applied to determine the most probable mechanism and the kinetic parameters. The results show that the thermal dehydration of La2(CO3)3·3.4H2O is a kind of three-step competitive reaction, and controlled by ann-order initial reaction followed byn-order competitive reaction (FnFnFnmodel). The activation energy matching with the most probable model is close to value obtained by Friedman method. The fitting curves match the original TG-DTG curves very well.