摘要：为了解决粉煤灰空心微珠白度不高的问题, 以粉煤灰空心微珠煅烧样为原料, 以NaOH和MgSO4为包覆剂, 采用非均匀形核法制备了一种纳米Mg (OH) 2包覆粉煤灰空心微珠复合粉体材料;采用白度仪、粒度仪、比表面积仪、X-射线衍射仪 (XRD) 、扫描电子显微镜 (SEM) 对复合粉体进行表征;研究不同工艺条件对复合粉体白度的影响。结果表明:当包覆量 (Mg (OH) 2与粉煤灰空心微珠质量之比) 为50%, 包覆剂双加, 反应温度为80℃时, 空心微珠白度由27.1%提高至51.2%, 粒径D98由60.81μm增大至66.72μm, 比表面积由4.512 m2/g增大到31.697 m2/g。XRD、SEM测试结果表明:空心微珠表面包覆了纳米片状Mg (OH) 2。该复合粉体有望应用在塑料填料和污水处理领域。
关键词：粉煤灰空心微珠；纳米氢氧化镁；白度；非均匀形核
Abstract：In order to solve the problem of low whiteness of fly-ash cenospheres, the paper takes calcined fly-ash cenospheres as raw materials, Na OH and MgSO4 as the coating agents, composite powder of fly-ash cenospheres coated with Mg (OH) 2 nano-particles was prepared with heterogeneous nucleation method.The composite powers were characterized by the whiteness analyzer, particle size analyzer, specific surface area analyzer, X-ray diffractometer (XRD) and scanning electron microscope (SEM) . The effect of different factors on the whiteness of the composite powders was studied. The results show that the whiteness increases from 27.1% to 51.2%, the particle size of D98 increases from 60.81 μm to 66.72 μm, the specific surface area increases from 4.512 m2/g to 31.697 m2/g when the coating amount is 50%, the coating agents are dropped at the same time and the reaction temperature is 80 ℃. XRD and SEM show that the surface of fly-ash cenospheres is coated with nano-lamellar Mg (OH) 2. The composite powder is expected to be used in the field of filling plastics and sewage treatment.
Keywords： fly-ash cenospheres ； Mg （OH）2 nano-particle ；whiteness； heterogeneous nucleation
