烧结温度对刚玉斜锆石复相陶瓷粉体的性能影响

以ZrOCl2.8H2O和AlCl3.6H2O为主要原料,采用溶胶-凝胶法制备化学成分均匀的刚玉斜锆石复合粉体,研究了不同焙烧温度对复合粉体体积密度、烧成收缩以及抗弯强度的影响,采用X射线衍射(XRD)、扫描电镜(SEM)测试手段分析了不同烧结温度下所得试样的矿物组成和微观结构。结果表明,随着烧结温度的提高,试样收缩率变大,烧结体密度不断增大,晶粒尺寸均匀,当烧成温度为1400℃时,复合粉体获得了最佳力学性能,抗弯强度达620MPa,当烧成温度为1600℃时,其体积密度最大为5.1g/cm3,并形成了结晶完好的刚玉斜锆石复相陶瓷粉体。

从玻璃熔窑的材料选择看其行业的技术进步

玻璃熔窑是常用的热工设备。近几年来,随着玻璃熔窑内衬耐火材料选择的发展,玻璃工业也取得了长足的进步,而对耐火材料的要求也越来越苛刻。在这种情况下,只有少数企业能生产出符合要求的耐火材料,他们生产的耐火材料技术指标比现有的国家标准更高,正是这些大型企业生产出满足了玻璃熔窑使用条件的耐火材料,材料成本和稳定的质量这两方面实在是难以取舍,本文就近期涉足省内某企业建造中型玻璃熔窑的材料选择,看其该行业的技术进步和我省耐火材料工业发展滞后的实际状态。

Preparation and sintering properties of zirconia-mullite-corundum composites using fly ash and zircon

Zirconia-mullite-corundum composites were successfully prepared from fly ash,zircon and alumina powder by a reaction sintering process.The phase and microstructure evolutions of the composite synthesized at desired temperatures of 1 400,1 500 and 1 600°C for 4 h were characterized by X-ray diffractometry and scanning electronic microscopy,respectively.The influences of sintering temperature on shrinkage ratio,apparent porosity and bulk density of the synthesized composite were investigated.The formation process of the composites was discussed in detail.The results show that the zirconia-mullite-corundum composites with good sintering properties can be prepared at 1 600°C for 4 h.Zirconia particles can be homogeneously distributed in mullite matrix,and the zirconia particles are around 5μm.The formation process of zirconia-mullite-corundum composites consists of decomposition of zircon and mullitization process.

利用41#FCAZS废料制备AZE复合粉体的研究

研究了用酸浸法去除41#熔铸锆刚玉(FCAZS)废料中以玻璃相存在的二氧化硅制备刚玉-斜锆石(AZE)复合粉体的可行性。采用正交试验方法对含有约70%AZE结构的41#FCAZS废料进行脱硅实验研究,考察了影响脱硅效果的4个主要因素,确定了最佳工艺参数,得到了纯度较高的AZE陶瓷复合粉。实验结果表明,各因素对酸浸法去除二氧化硅的影响次序为:酸用量(A)、酸浸浓度(B)、粉体粒度(C)、酸浸时间(D)。实验确定最佳工艺条件为:酸用量为143%,酸浸浓度为28%,原料粒径为40μm以下,酸浸时间为2.5 h;在此条件下SiO2的去除率可达97.67%;AZE陶瓷复合粉的回收率为74.74%。

Preparation of β-Sialon/ZrN bonded corundum composites from zircon by nitridation reaction sintering process

β-Sialon/ZrN bonded corundum composites were synthesized using fused white corundum,alumina micro powder,zircon and carbon black by nitridation reaction sintering process. Phase composition and microstructure of the synthesized composites were investigated by X-ray powder diffraction and scanning electronic microscope,and the formation process of the composites was discussed. The results show that the composites with different compositions can be obtained by controlling the heating temperature and contents of zircon and carbon black. The proper temperature to synthesize the composites is 1773 K.