新型结合剂SioxX-Zero对喷煤管用无水泥浇注料显微结构和性能的影响

喷煤管是水泥回转窑的关键承力部位,长期承受高温熟料粉尘和气流的剧烈冲刷,需具备优异的高温力学性能。本工作分别以新型SioxX-Zero和传统铝酸钙水泥为结合剂,采用板状刚玉、α-Al₂O₃微粉和碳化硅等为主要原料,分别在1 100 ℃和1 400 ℃热处理3 h,制备了喷煤管用无水泥和低水泥结合Al₂O₃-SiC质浇注料,并研究了新型SioxX-Zero结合剂对浇注料显微结构、常规物理性能和高温力学性能的影响。结果表明:与传统铝酸钙水泥相比,SioxX-Zero能有效提高浇注料流动值和延缓流动值衰减,改善其施工性能。同时,含SioxX-Zero的Al₂O₃-SiC质浇注料中原位生成了数量较多、尺寸较大的针状莫来石,大幅改善了材料的常温抗折/耐压强度、高温抗折强度和高温耐磨性能。

Effect of Novel Binder SioxX-Zero on Microstructure and Properties of No-Cement Castables for Coal Burner Pipe

As the key bearing component of cement kiln, the coal burner pipe is subjected to severe long-term abrasion by high temperature clinker dust and airflow, thus requires better high temperature mechanical properties. In this work, the novel SioxX-Zero and traditional calcium aluminate cement were used as binders to prepare no-cement and low-cement Al₂O₃-SiC castables for coal burner pipe. All castable specimens applied tabular corundum, α-Al₂O₃ powder and SiC as main raw materials, and should be fired at 1 100 ℃ and 1 400 ℃ for 3 h. The effect of SioxX-Zero on microstructure, physical properties and high temperature mechanical properties for castables were investigated. The results show that, compared with traditional calcium aluminate cement, the introduction of SioxX-Zero increases flowability and delays flowability decrease of castables, improving the workability. Moreover, more needle-liked mullite with larger size in-situ forms in Al₂O₃-SiC castables containing SioxX-Zero, which significantly enhances the cold modulus of rupture, cold crushing strength, hot modulus of rupture and high-temperature abrasion resistance.