Ash Evaluation of Indonesian Coal Blending for Pulverized Coal-Fired Boilers

Table 2

Recommended values for the evaluation of fouling factor, ash fusibility factor, and silica ratio.

Fouling factor ()	Ash fusibility factor ()	Silica ratio ()	Criterion
<0.2	>1,343	>72	Low
0.2–0.5	1,232–1,343	72 ≥  > 65	Medium
0.5–1	1,149–1,232	<65	High
>1	<1,149	—	Very high