The Effect of Additive on Sodium Transformation and Existing Forms during Zhundong Coal Combustion

By means of ICP and XRF, the migration characteristics of sodium and ash fusion characteristics of the typical ZDC were studied in this article. The results indicate that most of sodium in ZDC and its ashes is in water soluble form, and most of the organically-bound sodium and few water-bound sodium is released during 500∼600°C and 700∼800°C. Both kaolin and silica additive can reduce the emission of sodium compounds effectively during ZDC combustion. With the increase of mixed ratio of additives, the effect is more obvious. And the reduction effect of SiO₂ is better than that of kaolin, though kaolin can turn water souluble sodium to aluminosilicate more easily which is stable and water insoluble. (paper)