摘要
利用现代分析测试技术 ,对华能南京电厂粉煤灰中玻璃微珠的一些物理性质和微结构特征 ,如形貌、粒径分布、颗粒类型和化学成分、矿物相种类和含量、漂珠的丰度、微珠的密度和壳壁厚度以及热稳定性等进行了详细研究 ,并对其成因机制进行了讨论。空心微珠包括各种复珠的形成 ,主要与煤的成分和微结构有关 ,也与煤粒的燃烧过程有一定的联系。
Although the problem of effective utilization of coal powder fly ash(CPFA) has given rise to wide attention for last twenty years, yet only less than half of useful CPFA in China is presently utilized Alternative way to the problem of CPFA disposal would be to make use of mineral matter in the ash. Under the existing economic conditions, one of the resource components of coal ash which may be considered for their intrinsic value is the glass microspheroids (including cenospheres) The physical and microstructural characteristics of the glass microspheroids in CPFA from the Huaneng Nanjing Electic Power Plant, such as shape, particle size distribution, types of particles, chemical compositions, species and contents of mineral phases, weight percentage of cenospheres, density and crustal thickness of microspheroids, as well as their thermal stability etc , were studied by the modern analytical techniques in detail and the formation mechanism of cenospheres were discussed in this paper Cenospheres make up only less than 0 5% of the CPFA from the Nanjing Electric Power Plant The particle size distribution of the cenospheres shows that the particles with diameter less than 80μm are about 14 7%; between 80μm and 150um, about 58 4%; more than 150μm, about 26 9% The chemical compositions of cenospheres are similar to CPFA in SiO 2 and Al 2O 3, but higher in CaO and K 2O, and lower in Fe 2O 3 than those of CPFA The main mineral component of the cenospheres is a glass phase(more than 90%). The crystalline phases include only α quartz (absence of β quartz) and mullite The microspheroids which are sinkable in water have the chemical composition similar to CPFA. Their main mineral component is also a galss phase, and the crystalline phases are the same as CPFA including α quartz, β quartz, mullite, magnetite and hematite etc The formation mechanism of glass microspheroids (including cenospheres) is closely related to the petrographic composition and microstructure of coal, as well as its combustion in different conditions The tests of coal combustion at high temperatures show that the coal containing more volatiles is favourable for formation of cenospheres. The micropores in coal have much a greater effect on the formation of glass microspheroids than the submicropores.Much work remains to be done in this area [KH2D][WT5HZ]
出处
《高校地质学报》
CAS
CSCD
2000年第1期80-88,共9页
Geological Journal of China Universities
基金
江苏省自然科学基金!(编号BK95 0 182 0 9)
南京大学分析测试基金资助项目
关键词
粉煤灰
空心微珠
微结构
成因机制
矿物相
glass microspheroids
cenosphere
microstructure
formation mechanism
Nanjing Electric Power Plant
