School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
J Hazard Mater. 2011 Nov 30;196:370-9. doi: 10.1016/j.jhazmat.2011.09.045. Epub 2011 Sep 16.
A Microwave Melting Reactor (MMR) was designed in this study which improved the microwave adsorption of sewage sludge to prepare glass-ceramics. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were used for the study of crystallization behavior and microstructure of the developed glass-ceramics. DSC and XRD analysis revealed that crystallization of the nucleated specimen in the region of 900-1000°C resulted in the formation of two crystalline phases: anorthite and wollastonite. When the crystallization temperature increased from 900 to 1000°C, the tetragonal wollastonite grains were subjected to tensile microstresses, causing the cracking of crystal. Al ions substituted partially Si ions and occupied tetrahedral sites, giving rise to the formation of anorthite. The relationship between microwave irradiation and crystal growth was studied and the result indicated that the microwave selective heating suppressed the crystal growth, giving apparent improvements in the properties of the glass-ceramics. The glass-ceramics products exhibited bending strength of 86.5-93.4 MPa, Vickers microhardness of 6.12-6.54 GPa and thermal expansion coefficient of 5.29-5.75 × 10(-6)/°C. The best chemical durability in acid and alkali solutions was 1.32-1.61 and 0.41-0.58 mg/cm(2), respectively, showing excellent durability in alkali solution.
本研究设计了一种微波熔融反应器（MMR），以提高污水污泥的微波吸附能力，从而制备微晶玻璃。采用差示扫描量热法（DSC）、X 射线衍射（XRD）和扫描电子显微镜（SEM）研究了所开发的微晶玻璃的结晶行为和微观结构。DSC 和 XRD 分析表明，晶种在 900-1000°C 区域的结晶导致形成两种晶相：钙长石和硅灰石。当结晶温度从 900°C 升高到 1000°C 时，四方硅灰石晶粒受到拉伸微应力的作用，导致晶体开裂。Al 离子部分取代 Si 离子并占据四面体位置，形成钙长石。研究了微波辐射与晶体生长的关系，结果表明微波选择性加热抑制了晶体生长，明显改善了微晶玻璃的性能。微晶玻璃制品的抗弯强度为 86.5-93.4 MPa，维氏硬度为 6.12-6.54 GPa，热膨胀系数为 5.29-5.75×10(-6)/°C。在酸和碱溶液中的最佳耐化学腐蚀性分别为 1.32-1.61 和 0.41-0.58 mg/cm(2)，在碱溶液中表现出优异的耐久性。
