尖晶石包覆骨料对镁铝质耐火材料抗热震性和抗水泥熟料侵蚀的影响

Effect of Spinel-Coated Aggregates on Thermal Shock Resistance and Cement Clinker Corrosion Resistance of Magnesia Spinel Refractories

由于周期性水泥熟料回转以及进出料,水泥回转窑用耐火材料需要兼顾优异的耐火度、热震稳定性和耐侵蚀性。本研究通过将尖晶石细粉包裹于镁砂骨料表面,制备出含包覆结构骨料的方镁石–镁铝尖晶石耐火材料,并采用三点弯曲测试结合数字图像相关以及声发射技术表征其断裂行为,以及采用静态抗渣法表征其抗侵蚀性能。结果表明:通过改变尖晶石分布,形成包覆结构复合骨料,降低了氧化铝含量,尖晶石相达到更为均匀且广泛的分散。与氧化铝含量(质量分数)为10%的市售预合成尖晶石骨料耐火材料相比,采用尖晶石包覆骨料的方镁石–尖晶石耐火材料(Al2O3含量为5%)在保证材料抗热震性能的同时,提升了力学强度、热震稳定性能以及抗侵蚀能力。

Cement rotary kilns using refractories require excellent refractoriness,thermal shock stability and corrosion resistance due to the cyclic rotation and feeding–discharging of cement clinker.In this paper,a kind of magnesia–alumina spinel refractory containing coating structured aggregates were prepared by wrapping spinel fines on the surface of magnesia aggregates.The fracture behavior and corrosion resistance of prepared refractories were characterized by three-point bending test combined with digital image correlation,acoustic emission technique,and static slag resistance method.The results indicate that by changing the distribution of spinel to make coating structure aggregates,the alumina content is effectively reduced while a more uniform and extensive distribution of spinel phase is achieved.Compared with the merchant magnesia–alumina spinel refractory(10%Al2O3)with pre-synthetic spinel aggregates,the magnesia–alumina spinel refractory(5%Al2O3)with spinel coating aggregates has the improved mechanical strength and corrosion resistance,and maintains the thermal shock resistance.