(1. 广州有色金属研究院 资源综合利用研究所，广州 510650；
2. 中南大学 资源加工与生物工程学院，长沙 410083)
摘 要: 采用纯物质试验、等温还原法和微观结构分析法研究硫酸钠和碳酸钠对高铝铁矿钠化还原动力学规律的影响。结果表明：铁-铝-硅氧化物体系添加钠盐还原焙烧时，铁氧化物的还原转变规律为Fe3+→FeO→Fe，其中在还原初期30 min以内，添加硫酸钠时，铁氧化物的还原较添加碳酸钠的要快。硫酸钠和碳酸钠均能显著提高高铝铁矿的金属化率和还原度，加快还原反应速率，在还原初期30 min以内，不添加钠盐时还原反应速率常数为2.31，添加碳酸钠时升高到3.34，添加硫酸钠时达到3.92。高铝铁矿石还原初期(15 min以内)，以硫酸钠为添加剂，球团内部金属铁晶粒明显，铁晶粒粒径范围为1~10 μm；以碳酸钠为添加剂，球团内部金属铁晶粒几乎不可见，边缘可见铁晶粒与脉石成分连生。
关键字: 高铝铁矿石；硫酸钠；碳酸钠；还原；动力学
（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
