工程科学学报
工程科學學報
공정과학학보
Journal of University of Science and Technology Beijing
2015年
10期
1291-1295
,共5页
张伟%郁肖兵%李琳%邹宗树%齐渊洪%薛正良
張偉%鬱肖兵%李琳%鄒宗樹%齊淵洪%薛正良
장위%욱초병%리림%추종수%제연홍%설정량
磁铁矿%浮氏体%铁氧化物%非化学计量%还原%热力学平衡
磁鐵礦%浮氏體%鐵氧化物%非化學計量%還原%熱力學平衡
자철광%부씨체%철양화물%비화학계량%환원%열역학평형
magnetite%wustite%iron oxides%nonstoichiometry%reduction%thermodynamic equilibrium
铁氧化物是具有非化学计量比的化合物,非化学计量对铁氧化物的还原过程带来一系列影响。本文采用Dieckmann缺陷模型和Weiss的浮氏体理想固溶体模型分别对非化学计量比的磁铁矿和浮氏体进行了热力学计算。同时根据电荷守恒和物质守恒,对铁氧化物固溶体的综合缺陷度δ与还原失重率和亚铁含量的关系进行了分析,以期对实验终产物的判定提供依据。通过理论分析与计算,最终明确了不同化学计量比的磁铁矿和浮氏体在不同温度下的平衡还原势PCO(H2),即相应的优势区图。在给定还原势的纯赤铁矿等温还原过程(未有金属Fe生成时),当失重率小于6%时,还原产物属于Fe3+占优势的磁铁矿区域;当失重率高于6%时,反应进入Fe2+占优势的浮氏体区域。
鐵氧化物是具有非化學計量比的化閤物,非化學計量對鐵氧化物的還原過程帶來一繫列影響。本文採用Dieckmann缺陷模型和Weiss的浮氏體理想固溶體模型分彆對非化學計量比的磁鐵礦和浮氏體進行瞭熱力學計算。同時根據電荷守恆和物質守恆,對鐵氧化物固溶體的綜閤缺陷度δ與還原失重率和亞鐵含量的關繫進行瞭分析,以期對實驗終產物的判定提供依據。通過理論分析與計算,最終明確瞭不同化學計量比的磁鐵礦和浮氏體在不同溫度下的平衡還原勢PCO(H2),即相應的優勢區圖。在給定還原勢的純赤鐵礦等溫還原過程(未有金屬Fe生成時),噹失重率小于6%時,還原產物屬于Fe3+佔優勢的磁鐵礦區域;噹失重率高于6%時,反應進入Fe2+佔優勢的浮氏體區域。
철양화물시구유비화학계량비적화합물,비화학계량대철양화물적환원과정대래일계렬영향。본문채용Dieckmann결함모형화Weiss적부씨체이상고용체모형분별대비화학계량비적자철광화부씨체진행료열역학계산。동시근거전하수항화물질수항,대철양화물고용체적종합결함도δ여환원실중솔화아철함량적관계진행료분석,이기대실험종산물적판정제공의거。통과이론분석여계산,최종명학료불동화학계량비적자철광화부씨체재불동온도하적평형환원세PCO(H2),즉상응적우세구도。재급정환원세적순적철광등온환원과정(미유금속Fe생성시),당실중솔소우6%시,환원산물속우Fe3+점우세적자철광구역;당실중솔고우6%시,반응진입Fe2+점우세적부씨체구역。
Iron oxides were nonstoichiometric chemical compounds. Their reduction processes were remarkably influenced by non-stoichiometries. Dieckmann’ s defect model of magnetite and Weiss’ s ideal solid solution model of wustite were adopted to analyze the thermodynamic influences on the reduction processes. The dependences of deficiency degreeδon weight loss and Fe2+ mole ratio were analyzed by using the charge conservation and mass conservation principles. These relationships were recommended to judge the final product of the reduction processes. According to theoretical analyses and calculations, the predominance area diagrams including dif-ferent nonstoichiometries of magnetite and wustite were determined in equilibrium with the reduction potentials PCO(H2) at different tem-peratures. It comes to a conclusion that when the reduction weight loss ratio is less than 6% ( without metallic Fe) , magnetite is pre-dominant in the pure hematite reduction at a certain temperature and reduction potential; but when the reduction weight loss ratio is higher than 6%, the process then enters the zone of wustite.