【作者】 陈俊；

【导师】 王周福；

【作者基本信息】 武汉科技大学 ， 材料学， 2010， 硕士

【摘要】 随着环保意识的加强,铬公害问题越来越受到重视,镁铬砖必将逐渐被取代。镁质和镁尖晶石质耐火材料是重要的碱性耐火材料,本文以无铬化为目的,研究了添加稀土氧化物对镁质和镁尖晶石质材料性能的影响。以不同粒度的电熔镁砂和化学纯的稀土氧化物细粉为主要原料,纸浆废液为结合剂,制成含稀土氧化物的镁质耐火材料,研究了Y2O3、CeO2、La2O3、Nd2O3对镁质耐火材料物理性能、挂窑皮性及抗渣性能的影响。结果表明:(1)稀土氧化物都能促进镁质耐火材料的烧结,其中以添加CeO2效果最好;(2)稀土氧化物能提高材料的力学性能,其中少量的Y2O3、CeO2、Nd2O3就能提高镁质材料的常温力学性能,而La2O3是在加入量为1.5%时,性能最好;(3)添加1%的Y2O3对试样的高温抗折强度提高最大,达到8.19MPa,其次是添加La2O3和Nd2O3的试样;(4)加入Y2O3后,材料的挂窑皮性能有了很大的提高,而加入La2O3、Nd2O3后,材料挂窑皮性能有一定提高,加入CeO2后,挂窑皮性能无明显改善;(5)加入稀土氧化物提高了镁质耐火材料抗RH精炼炉渣侵蚀的能力。以不同颗粒级配的电熔镁砂、活性α-Al2O3细粉、镁铝尖晶石细粉和化学纯的稀土氧化物细粉为主要原料,制成含稀土氧化物的镁尖晶石质耐火材料,研究了Y2O3、La2O3、Nd2O3、CeO2对镁尖晶石质耐火材料物理性能、挂窑皮性及抗渣性能的影响。结果表明:(1)添加稀土氧化物能促进镁尖晶石质耐火材料的烧结,其中以添加Y2O3效果最好;(2)适量的稀土氧化物能提高镁尖晶石质材料的常温力学性能;(3)加入稀土氧化物,有利于提高镁尖晶石质材料的热震稳定性;稀土氧化物有利于提高镁尖晶石质材料的高温抗折强度,其中以加入1%CeO2效果最好,为3.76MPa;(4)加入Y2O3后,材料的挂窑皮性能有了很大的提高,而加入La2O3、Nd2O3后,材料挂窑皮性能有一定提高;加入CeO2后,材料的挂窑皮性能无明显改善;(5)加入稀土氧化物有利于提高镁质耐火材料抗RH精炼炉渣侵蚀的能力。对镁质材料和镁尖晶石质材料的挂窑皮性及抗渣性进行了对比,结果表明:镁质材料的挂窑皮性能好于镁尖晶石质材料,镁尖晶石质材料抗RH精炼炉渣侵蚀的能力要好于镁质材料。更多还原

【Abstract】 With the reinforcement of environmental awareness, more attentions have been paid to the pollution of chrome, resulting in the gradual replacement of magnesia-chrome brick. Magnesia and magnesia-spinel refractories are important basic refractories,. On the purpose of eliminating chrome pollution, the effects of added rare earth oxides on the properties of the magnesia and magnesia-spinel refractories were studied in this paper.Magnesia refractories were prepared using MgO and rare earth oxides(Y2O3, La2O3, Nd2O3, CeO2) power as raw materials and waste solution of pulp as binder. The effects of rare earth oxides addition on physical performance, the coating adhering performance and slag resistance performance of magnesia refractories were studied. The results indicated that the addition of rare earth oxides was beneficial to the sintering densification of magnesia refractories, and the best was CeO2; mechanical performance of samples can be improved by the proper addition of rare earth oxides, and the mechanical performance at room temperature can be improved by addition of a small quantity of Y2O3, CeO2, Nd2O3; however, the best adding quantity for La2O3 was 1.5wt.%; The highest HMOR of samples containing 1wt.% Y2O3 was 8.19 MPa, and the next were La2O3 and Nd2O3, but for CeO2 there is no significant improvement on the HMOR. The coating adhering performance of magnesia refractory has highly increased by adding Y2O3, no obvious improvement by addition of CeO2, and a little improvement with La2O3 and Nd2O3. The RH slag resistance performance of magnesia refractories increased with the addition of rare earth oxides.Magnesia-spinel refractories were prepared using MgO,α-Al2O3, MA power and rare earth oxides(Y2O3, La2O3, Nd2O3, CeO2) as raw materials and waste solution of pulp as binder. The effects of rare earth oxides addition on physical performance, coating adhering performance and slag resistance performance of magnesia-spinel refractories were studied. The results showed that the addition of rare earth oxides were beneficial to the sintering densification of magnesia-spinel refractories, and the addition of Y2O3 with a better outcome; the mechanical performance at room temperature of samples could be improved by the proper addition of rare earth oxides;The addition of rare earth oxides were beneficial to the thermal shock resistance of magnesia-spinel refractories, the sample with 1wt.% CeO2 has the highest HMOR of 3.76MPa. The coating adhering performance of magnesia-spinel refractory has highly increased by adding Y2O3, no obvious improvement by addition of CeO2, and a little improvement with La2O3 and Nd2O3. The RH slag resistance performance of magnesia-spinel refractories increased with the addition of rare earth oxides.The coating adhering performance and slag resistance performance of magnesia and magnesia-spinel refractories were compared. The results showed that the coating adhering performance of magnesia refractories were better than that of magnesia-spinel refractories, and the RH slag resistance performance of magnesia-spinel refractories were better than that of magnesia refractories.更多还原