珞璜电厂粉煤灰微珠的精细化分选

 针对华能集团重庆珞璜电厂煤粉炉粉煤灰的利用问题,采用XRF、XRD、Siroquant 定量、SEM-EDS 及光学显微镜等技术手段,在深入分析煤粉炉粉煤灰的岩石学、矿物学、元素地球化学特征的基础上,对此类粉煤灰的微珠进行浮沉、弱磁选和气流分级等精细化分选实验研究。结果显示,以水为介质的浮沉实验可获得质量分数0.15%的漂珠;磁场强度208×10³ A/m 湿式弱磁选实验可获得质量分数14.8%、Fe₂O₃含量44.65%的磁珠;气力旋流分级实验可获得中值粒径分别为89.6、40.2、21.3、12.7、8.1、4.9 μm 共6 个粒度级的粉煤灰微珠产品,表明通过精细化分选获得的粉煤灰微珠产品能够适应多种领域的应用,显著提高此类粉煤灰的高值利用率。

Experiments on fine separation of microspheres from fly ash of Luohuang coal-fired power plant

The petrological, mineralogical and chemical characteristics of the fly ash from Luohuang coal-fired power plant of Huaneng Group in Chongqing, China were studied using XRF, XRD, Siroquant, SEM-EDS, and optical microscope. Experiments of sink-float separation, magnetic separation and size grading were carried out based on analyses of those characteristics for improving the utilization rate and added value of the fly ash. As the experimental result indicated, cenospheres of 0.15% were separated by means of the water-medium sink-float separation first; then magnetic microspheres (with Fe₂O₃ content of 44.65%) were available through the wet low-intensity magnetic (260 mT) separation; finally an air classification of the remaining non-magnetic microspheres was applied to obtain microspheres with six different size fraction: 89.6, 40.2, 21.3, 12.7, 8.1 and 4.9 μm. According to the above fine separation procedure, a variety of fly ash sphere products adapting to special application fields can be acquired, improving both the utilization rate and added economic value of Luohuang fly ash. Meanwhile, the environmental pressure caused by the fly ash will be relieved effectively.