PF Fineness Problem

Before replacement of elements fineness was OK?

Check the condition of the classifier blades wear-out.

Check and if required bowl DP (may be too high)

How is the mill reject?

I agree inspection of the classifier section would be one step. When you do this I would also look for holes in the classifier cone and feed pipe. I would also look for excessive primary airflow. Has their been an significant decrease in motor amperage and Mill differential? Has their been a change in coal hardness or moisture? Was anything else replaced during the down time?

I would also look for excessive primary airflow

I wanted to add that but had already submitted the response and then I didn't want to add a post for a point. My experience says that the coal air ratio has been maintained too off recommended value (to reduce the rejects) and that often compromises on the mill performance and wear life.

Especially this could have been disturbed just before the grinding media replacement, when due to wornout media obviously the rejects could have been higher.

Response form OP?