<th id="5nh9l"></th><strike id="5nh9l"></strike><th id="5nh9l"><noframes id="5nh9l"><th id="5nh9l"></th><strike id="5nh9l"></strike>
<progress id="5nh9l"><noframes id="5nh9l"><th id="5nh9l"><noframes id="5nh9l">
<th id="5nh9l"></th> <strike id="5nh9l"><noframes id="5nh9l"><span id="5nh9l"></span>
<progress id="5nh9l"><noframes id="5nh9l"><span id="5nh9l"><noframes id="5nh9l"><span id="5nh9l"></span><strike id="5nh9l"><noframes id="5nh9l"><strike id="5nh9l"></strike>
<span id="5nh9l"><noframes id="5nh9l">
<span id="5nh9l"><noframes id="5nh9l">
<span id="5nh9l"></span><span id="5nh9l"><video id="5nh9l"></video></span>
<th id="5nh9l"><noframes id="5nh9l"><th id="5nh9l"></th>
<progress id="5nh9l"><noframes id="5nh9l">

紅格含鉻釩鈦磁鐵礦球團礦物學和等溫氧化動力學

Mineralogical characteristics and isothermal oxidation kinetics of Hongge chromium containing vanadium and titanium magnetite pellets

  • 摘要: 研究了紅格釩鈦磁鐵礦(HCVTM)球團等溫氧化動力學及其礦物學特征. 在不同的溫度(1073~1373 K)和不同的時間(10~60 min)范圍內,對HCVTM球團礦進行了等溫氧化動力學實驗. 首先分析了球團在不同溫度和時間下的微觀結構和礦物組成規律. 然后根據定義的氧化率,計算和分析了氧化率及其變化規律,以及礦相結構對氧化率的影響. 最后結合縮核模型、修正的氧化率函數和阿倫尼烏斯公式,計算了反應速度常數、修正系數和反應活化能,并判斷了反應限制性環節. 研究表明:隨溫度的提高,低熔點液相增加,赤鐵礦晶粒的生成、長大和再結晶,形成連續的黏結相,空隙數量減少. 隨時間的增加,生成的液相促進了赤鐵礦晶粒間的黏結和長大,但是晶粒間硅酸鹽相和鈣鈦礦類物相惡化了球團結構. 同時,鈣鈦礦和鐵板鈦礦相生成. HCVTM球團礦空隙數量的減少和黏結相的生成,表現在氧化速率隨時間增加而減慢. HCVTM球團氧化反應主要受擴散控制,球團氧化前期的反應活化能為13.74 kJ·mol-1,氧化后期的活化能為3.58 kJ·mol-1,氧化率函數的修正參數u2=0.03.

     

    Abstract: The isothermal oxidation kinetics and mineralogical characteristics of Hongge chromium containing vanadium and titanium magnetite (HCVTM) pellets were investigated. The experiments related to the isothermal oxidation kinetics were performed over a temperature range of 1073 to 1373 K and a time range of 10 to 60 min. First, the microstructure and variations in the mineral composition of the pellets were analyzed. Further, the oxidation rate and its change regulation were calculated and analyzed by combining the defined oxidation rate function, and the effects of the mineral phase structures on the rate of oxidation were determined. Finally, the modified oxidation rate function, Arrhenius equation, reaction rate constant, correction factor, and reaction activation energy were calculated by combining the shrinking core model, and the restrictive step in the oxidation reaction was determined. The results depict that an increase in temperature causes an increase in the low melting point liquid phase; formation, growth, and recrystallization of hematite grains; and formation of a bonding phase. Additionally, it causes a decrease in the number of interspaces. With an increase in time, the bonding and growth of hematite grains are promoted due to the generation of a liquid phase. However, the structure of pellets is observed to deteriorate due to the formation of silicate and perovskite phases. Meanwhile, perovskite, and pseudobrookite phases are also generated. Oxidation rate decreased with increasing time due to the decrease in the number of interspaces and bonding phases. In HCVTM pellets, the oxidation reaction is controlled by diffusion. The activation energy of the initial reaction is 13.74 kJ·mol-1 while that of the latter reaction is 3.58 kJ·mol-1. Further, the corrected parameter for the oxidation rate function is observed to be 0.03.

     

/

返回文章
返回
<th id="5nh9l"></th><strike id="5nh9l"></strike><th id="5nh9l"><noframes id="5nh9l"><th id="5nh9l"></th><strike id="5nh9l"></strike>
<progress id="5nh9l"><noframes id="5nh9l"><th id="5nh9l"><noframes id="5nh9l">
<th id="5nh9l"></th> <strike id="5nh9l"><noframes id="5nh9l"><span id="5nh9l"></span>
<progress id="5nh9l"><noframes id="5nh9l"><span id="5nh9l"><noframes id="5nh9l"><span id="5nh9l"></span><strike id="5nh9l"><noframes id="5nh9l"><strike id="5nh9l"></strike>
<span id="5nh9l"><noframes id="5nh9l">
<span id="5nh9l"><noframes id="5nh9l">
<span id="5nh9l"></span><span id="5nh9l"><video id="5nh9l"></video></span>
<th id="5nh9l"><noframes id="5nh9l"><th id="5nh9l"></th>
<progress id="5nh9l"><noframes id="5nh9l">
259luxu-164