应用化学 ›› 2022, Vol. 39 ›› Issue (8): 1312-1318.DOI: 10.19894/j.issn.1000-0518.210469

• 研究论文 • 上一篇    下一篇

微氧化烧结制备掺杂Y2O3的SiC陶瓷及含镉模拟废水处理

王兵(), 唐敏, 王颖, 刘志光   

  1. 河南省安阳生态环境监测中心,安阳 455000
  • 收稿日期:2021-09-17 接受日期:2022-01-10 出版日期:2022-08-01 发布日期:2022-08-04
  • 通讯作者: 王兵

Preparation of Y2O3⁃Dopped SiC Ceramics by Micro⁃oxidation Sintering and Removal of Cd2+ in Mimic Wastewater

Bing WANG(), Min TANG, Ying WANG, Zhi-Guang LIU   

  1. Henan Anyang Ecological Environmental Monitoring Center,Anyang 455000,China
  • Received:2021-09-17 Accepted:2022-01-10 Published:2022-08-01 Online:2022-08-04
  • Contact: Bing WANG
  • About author:379928820@qq.com

摘要:

采用了微氧化烧结制备了不同Y2O3质量分数(0%、2%、4%、6%)的多孔SiC陶瓷,通过对陶瓷的晶体结构、微观形貌、物理性能和Cd2+的去除率测试发现:添加了Y2O3的SiC陶瓷出现了较多的第二相Y2SiO7、Y5Si3C0.5,随着Y2O3的质量分数增加逐渐升高,主相的衍射峰的强度有降低。扫描电子显微镜测试发现,SiC陶瓷的尺寸在2.5 μm,Y2O3引入后,SiC陶瓷的晶粒尺寸降低,高温烧结时液相的含量增加,熔体粘度降低,晶粒结合更加紧密,Y2O3的引入提高了多孔陶瓷的体积密度,Y2O3质量分数为6%SiC的体积密度最大为2.21 g/cm3。热导率随着Y2O3质量分数的增加呈现出先升高后降低的趋势。金属Cd2+的过滤测试表明:随着Y2O3质量分数增加,Cd2+的残留质量浓度、膜通量和去除率先降低后升高,当掺杂质量分数为4%时,Cd2+残留质量浓度最低为0.042 mg/L,膜通量达到了最大值572 L/(m2·h),去除率最大为99.95%,相比未掺质量分数杂体系的去除率提高了0.14%。随着溶液pH值的逐渐增大,金属Cd2+的残留质量浓度逐渐降低、去除率逐渐升高,pH≥9时最终均趋于稳定。综合来看,多孔SiC陶瓷的助烧剂Y2O3最佳掺量为4%。

关键词: 碳化硅, 微氧化烧结, 陶瓷, 助烧剂, Y2O3, pH值, 废水处理

Abstract:

Porous SiC ceramics with different mass fractions of Y2O3 (0%, 2%, 4%, 6%) were prepared by micro-oxidation sintering. The crystal structure, micro morphology, physical properties and metal Cd removal rate of the ceramic were characterized. The second phases Y2SiO7 and Y5Si3C0.5 increases with the increase of Y2O3 content, and the intensity of the diffraction peaks of the main phase decreases. Scanning electron microscopy analysis shows that the size of SiC ceramics is 2.5 μm. As the increase of Y2O3 content, the grain size of SiC ceramics is reduced, the content of liquid phase increases during high-temperature sintering, the melt viscosity is reduced, and the crystal grains are more tightly bonded. Considering the bulk density of porous ceramics, the maximum bulk density of SiC is 2.21 g/cm3 with a Y2O3 content of 6%, and the thermal conductivity increases first and then decreases with the increase of the Y2O3 content. The filtration test of metal Cd2+ in the wastwater shows that with the increase of Y2O3 content, the residual concentration, the trend of the membrane flux of SiC thin film, and the removal rate of Cd2+ first decrease and then increase. When the doping concentration is 4%, the minimum residual mass concentration of Cd2+ is 0.042 mg/L, the maximum membrane flux is 572 L/(m2·h), and the maximum removal rate is 99.95%, compared with the undoped system, the removal rate is increased by 0.14%. As the pH of the solution gradually increases, the residual concentration of metal Cd2+ gradually decreases and the removal rate gradually increases, and both stabilize under alkaline conditions when pH ≥9. On the whole, the best content of Y2O3 for porous SiC ceramics is 4%.

Key words: Silicon carbide, Micro-oxidation sintering, Ceramics, Sintering aid, Y2O3, pH, Wastewater treatment

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