由于缺乏成熟的大规模工业化处置技术,大量堆存的煤气化细灰造成严重的环境污染和资源浪费。流化熔融处置煤气化细灰可实现碳灰分离和灰分的改性提质,使灰分转变为富硅铝元素的玻璃相熔渣;泡沫微晶玻璃由于其特殊的玻晶交织结构使其具有良好的机械性能和保温隔热性能,确立了熔渣制备泡沫微晶玻璃的高值化利用思路。以煤气化细灰熔渣为原料,采用无机凝胶铸造工艺制备泡沫微晶玻璃,研究了主要工艺参数预固化时间和烧结温度对泡沫微晶玻璃析晶特性、孔结构和抗压强度的影响。结果表明:泡沫微晶玻璃析晶特性和孔结构与烧结温度、预固化时间均呈现相关性。较高的烧结温度可促进烧结过程中晶相析出进而强化泡沫微晶玻璃的抗压强度。预固化时间影响泡沫玻璃胚体的网络结构,导致晶相析出时克服的阻力不同,从而影响晶相种类。预固化时间30min时,泡沫玻璃胚体在烧结析晶过程中易发生大孔径孔隙坍塌。抗压强度随孔隙率的增大而减小,随孔径增加呈非线性减小。预固化时间为90min时,可获得良好的孔隙结构。抗压强度受到析晶特性和孔隙结构特性的共同作用。烧结温度900℃时可强化抗压强度,尤其是预固化时间90min时,泡沫微晶玻璃的抗压强度为3.77MPa;而700和800℃时,抗压强度是否增大与预固化时间相关。预固化时间60min、烧结温度900℃时,析出大量晶体,孔隙率为66.20%且孔径均匀分布,抗压强度为1.40MPa。

ous environmental pollution and resource waste. The treatment of coal gasification fine ash by fluidization melting can realize the separationof carbon and ash, and the modification and improvement of ash, so that ash can be transformed into glass phase slag rich in silicon andaluminum elements. Because of its special glassy interwoven structure, porous glass-ceramics have good mechanical properties and thermalinsulation properties, so the idea of high value utilization of molten slag to prepare porous glass-ceramics was established. The effects ofpre-curing time and sintering temperature on crystallization characteristics, pore structure and compressive strength of porous glass-ceramics were studied. The results show that the crystallization characteristics and pore structure of porous glass-ceramics are related to sintering temperature and pre-curing time. The higher sintering temperature can promote the crystal phase precipitation in the sinteringprocess and strengthen the compressive strength of the porous glass-ceramics. The pre-curing time affects the network structure of the porous-glass embryo, resulting in different resistance to be overcome during crystal precipitation, which affects the type of crystal phase.When the pre-curing time is 30 min, the large pore size of the porous-glass embryo is easy to collapse during the process of sinteringand crystallization. The compressive strength decreases with the increase of porosity and decreases nonlinearly with the increase of poresize. When the pre-curing time is 90 min, a good pore structure can be obtained. The compressive strength is influenced by the crystallization characteristics and the pore structure characteristics. When the sintering temperature is 900 ℃ , the compressive strength can bestrengthened, especially when the pre-curing time is 90 min, the compressive strength of the porous glass-ceramics is 3.77 MPa. At700 ℃ and 800 ℃ , whether the compressive strength increases is related to the pre-curing time. When the pre-curing time is 60 min andthe sintering temperature is 900 ℃ , a large number of crystals are precipitated, the porosity is 66.20%, the pore size is evenly distributed, and the compressive strength is 1.40 MPa.

0 引言

1 试验

   1.1 样品分析方法

   1.2 试验材料

   1.3 试验方法

2 试验结果与讨论

   2.1 泡沫玻璃胚体

   2.2 析晶特性

   2.3 孔结构

   2.4 抗压强度

3 结论