挤出滚圆法批量制备铁铜矿石复合氧载体

The Composite Oxygen Carriers Using Iron Ore and Copper Ore as Raw Materials and Prepared by Extrusion-Spheronization Method

本文采用挤出滚圆法批量制备以铜矿石和铁矿石的废弃细微粉末为原料的复合氧载体,以蒙脱石、浮石等作为粘结剂,实现氧载体颗粒内粉末的物理均匀混合、颗粒一次成型以及活性组分间的协同效应。首先优化挤出滚圆法工艺,主要考察制备颗粒的机械强度,发现FeCu-10M(蒙脱石质量分数为10%)和FeCu-5P(浮石质量分数为5%)表现出较高的破碎强度。随后在批次流化床中采用神华烟煤为燃料对其进行反应性测试,发现FeCu-10M的煤化学链燃烧性能优异,多次循环中仍保持良好的稳定性。XRD和SEM表征显示颗粒内没有发生明显副反应且无明显烧结、团聚现象.本研究表明挤出滚圆法适合大批量制备氧载体颗粒,所制备的铜铁矿石复合氧载体在反应性、循环稳定性和经济性等方面均具备良好的应用前景。

Composite oxygen carriers(OCs)using waste fine iron ore and copper ore powders as raw materials are prepared in batches by the extrusion-spheronization method in this work;a range of inert aluminosilicates(i.e.,montmorillonite,pumice,et al.)are added as binders to achieve physical uniform mixing of ore powders in the same oxygen carrier particles,one-time particle shaping and synergistic effects between active components.First,the extrusion-spheronization preparation process is optimized and the crushing strength of OC particle is evaluated.Experimental results show that the FeCu-10 M(using 10%(wt)montmorillonite as binders)and FeCu-5 P(with 5%(wt)pumice as binders)oxygen carriers show higher crushing strength.Subsequently,the coal-derived chemical looping combustion is performed in a batch fluidized bed.It is found that FeCu-10 M performs better as an oxygen carrier during in-situ gasification chemical looping combustion of Shenhua bituminous coal(bituminous).FeCu-10 M also demonstrates excellent combustion performance and well stable performance during multiple cycles.The XRD pattern and SEM characterization reveal that no obvious side reactions occur between different components within one particle,no significant sintering/agglomeration occurs between the particles.The experimental results in this work show that the extrusion-spheronization method is suitable for large-scale preparation of oxygen carrier particles.The iron-copper-ore composite oxygen carriers prepared by this method have good application promise in terms of reactivity,cycle stability,and economy.