废玻璃烧结多孔微晶玻璃的制备、气孔结构及其物性研究

发布时间：2018-05-02 22:03

本文选题：废玻璃 + 多孔微晶玻璃　；参考：《南昌航空大学》2015年硕士论文

【摘要】：多孔微晶玻璃是由无机非晶材料热处理得到的含有闭合孔或连通孔微晶材料,其性能取决于气孔、晶相和非晶相比例与结构,具有密度低、比表面积大、导热系数小、强度高、阻尼性能好等优异性能。利用废玻璃生产多孔微晶玻璃,不仅解决了废玻璃规模化利用,而且显著降低多孔微晶玻璃生产成本,简化生产工艺,具有显著经济和环保效益。本文以废玻璃粉为原料,采用低温烧结-高温发泡新型烧结工艺,优选发泡剂和烧结助剂,系统研究烧结工艺制度、发泡剂组成对气孔结构、晶相组成、表观密度、压缩强度和导热性能等影响规律,制备出轻质、孔径均匀可控、高强度多孔微晶玻璃及其复合板。发泡剂组份研究表明,以CaCO3为发泡剂时,随CaCO3含量增加,多孔微晶玻璃表观密度与抗压强度都是先减小后增大,孔隙率则与之相反,晶相为单一硅灰石结构,结晶度增大。CaCO3和Si C为复合发泡剂时,CaCO3降低SiC氧化温度,提高SiC氧化速率;SiC提高多孔微晶玻璃孔隙率,降低表观密度,提高硅灰石含量。纳米SiC使表观密度增大,孔隙率降低,气孔尺寸减小。多孔微晶玻璃导热系数随CaCO3含量增大而减小,导热系数为0.096~0.139 W/m·K。使用复合发泡剂时,随SiC含量增大,抗压强度与表观密度成正比,为0.7~4.7 MPa。烧结-发泡工艺实验表明,以CaCO3为发泡剂时,随烧结温度升高和时间延长,多孔微晶玻璃表观密度呈下降趋势,孔隙率增大。随发泡温度升高和时间延长,表观密度减小,平均孔径和孔隙率增大。多孔微晶玻璃抗压强度与表观密度呈直线正比关系,抗压强度为0.35~4.98 MPa。一次烧成多孔微晶玻璃复合板的关键在于调节釉料层原料成分,使其烧结和晶化温度处于多孔微晶玻璃低温烧结-高温发泡温度区间。发泡机理研究表明,废玻璃粉体在800?C下出现致密烧结,800~900?C之间出现气孔形核和长大,与本文工艺设计思路一致。这种低温烧结-高温发泡不仅适合废玻璃生产多孔微晶玻璃,对于其他固体废渣回收利用也具有参考价值。
[Abstract]:Porous glass-ceramics are obtained by heat treatment of inorganic amorphous materials with closed or connected pores. Their properties depend on the porosity, the proportion and structure of crystalline phase and amorphous phase, and have low density, large specific surface area, small thermal conductivity and high strength. Excellent damping property and so on. The production of porous glass-ceramics by waste glass not only solves the large-scale utilization of waste glass, but also significantly reduces the production cost of porous glass-ceramics, simplifies the production process, and has remarkable economic and environmental benefits. In this paper, using waste glass powder as raw material, a new sintering process of low temperature sintering and high temperature foaming was used to select foaming agent and sintering assistant. The sintering process system was studied systematically. The composition of foaming agent for pore structure, crystal phase composition, apparent density was studied systematically. The high strength porous glass-ceramics and its composite plate were prepared by the influence of compression strength and thermal conductivity. The results show that when CaCO3 is used as foaming agent, the apparent density and compressive strength of porous glass-ceramics decrease first and then increase with the increase of CaCO3 content, and the porosity is opposite, the crystalline phase is a single wollastonite structure. With the increase of crystallinity, Caco _ 3 and sic were used as composite foaming agents to decrease the oxidation temperature of SiC, increase the oxidation rate of SiC, increase the porosity of porous glass-ceramics, decrease the apparent density and increase the content of wollastonite. Nanometer SiC increases apparent density, decreases porosity and decreases pore size. The thermal conductivity of porous glass-ceramics decreases with the increase of CaCO3 content, and the thermal conductivity is 0.096 ~ (0.139) W / m ~ (K). When the compound foaming agent is used, the compressive strength is proportional to the apparent density with the increase of SiC content, which is 0.7 ~ 4.7 MPA. The experimental results of sintering and foaming process show that the apparent density of porous glass-ceramics decreases and the porosity increases with the increase of sintering temperature and time when CaCO3 is used as foaming agent. With the increase of foaming temperature and time, the apparent density decreases and the average pore size and porosity increase. The compressive strength of porous glass-ceramics is proportional to the apparent density, and the compressive strength is 0.35 ~ 4.98 MPA. The key of single firing porous glass-ceramics composite plate is to adjust the raw material composition of glaze layer so that the sintering and crystallization temperatures are in the range of low-temperature sintering and high-temperature foaming temperature of porous glass-ceramics. The study of foaming mechanism shows that the dense sintering of waste glass powder under 800C has the appearance of porosity nucleation and growth, which is consistent with the process design in this paper. This kind of low-temperature sintering and high-temperature foaming is not only suitable for producing porous glass-ceramics, but also has reference value for the recovery and utilization of other solid waste slag.
【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ171.733

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