(1. 廣州有色金屬研究院 資源綜合利用研究所，廣州 510650；
2. 中南大學(xué) 資源加工與生物工程學(xué)院，長沙 410083)
摘 要: 采用純物質(zhì)試驗(yàn)、等溫還原法和微觀結(jié)構(gòu)分析法研究硫酸鈉和碳酸鈉對(duì)高鋁鐵礦鈉化還原動(dòng)力學(xué)規(guī)律的影響。結(jié)果表明：鐵-鋁-硅氧化物體系添加鈉鹽還原焙燒時(shí)，鐵氧化物的還原轉(zhuǎn)變規(guī)律為Fe3+→FeO→Fe，其中在還原初期30 min以內(nèi)，添加硫酸鈉時(shí)，鐵氧化物的還原較添加碳酸鈉的要快。硫酸鈉和碳酸鈉均能顯著提高高鋁鐵礦的金屬化率和還原度，加快還原反應(yīng)速率，在還原初期30 min以內(nèi)，不添加鈉鹽時(shí)還原反應(yīng)速率常數(shù)為2.31，添加碳酸鈉時(shí)升高到3.34，添加硫酸鈉時(shí)達(dá)到3.92。高鋁鐵礦石還原初期(15 min以內(nèi))，以硫酸鈉為添加劑，球團(tuán)內(nèi)部金屬鐵晶粒明顯，鐵晶粒粒徑范圍為1~10 μm；以碳酸鈉為添加劑，球團(tuán)內(nèi)部金屬鐵晶粒幾乎不可見，邊緣可見鐵晶粒與脈石成分連生。
關(guān)鍵字: 高鋁鐵礦石；硫酸鈉；碳酸鈉；還原；動(dòng)力學(xué)
（1. Department of Resource Comprehensive Utilization, Guangzhou Research Institute of
Non-ferrous Metals, Guangzhou 510650, China;
2. School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:The effects of Na2SO4 and Na2CO3 on the sodium-reduction kinetics of high-aluminium iron ore were studied by pure material testing isothermal reduction method and microstructure analysis method. The results indicate that, when the Fe2O3-Al2O3-SiO2 system is reduced roasting with addition of sodium, the transformation law of iron oxide is as follows: Fe3+→FeO→Fe, and at the beginning of the reduction (within 30 min) with addition of Na2SO4, the iron oxide reduction rate is faster than that of Na2CO3. Both Na2SO4 and Na2CO3 can improve the metallization rate and reducibility of the high-aluminium iron ore, and accelerate the reduction reaction rate. At the beginning of the reduction(within 30 min), the reduction reaction rate constant is 2.31 when there is no sodium added, and the reaction rate constant rises to 3.34 with addition of Na2CO3, and the rate constant reaches 3.92 with addition of Na2SO4. At the beginning of the reduction(within 15 min), the metallic iron grain in the pellets is clear when using Na2SO4 as the addition, and the size of metallic iron grain is 1-10 μm. While there is almost no metallic iron grain in the pellets when using Na2CO3 as the addition, and the metallic iron grain associates with gangue at the edge of the pellet.
Key words: high-aluminium iron ore; sodium sulfate; sodium carbonate; reduction; dynamics
