I think you need to see the type of castable you are using. You need to use either a self flow type castable or a cement free gel bonded castable to minimise the abrasion and corrosion. The maximum grain size in that you can maintain 6 mm.

Pinaki

Dear N Jaye,

This is a common problem with number of plants, but any way there are a few more types of castables in market avialable for this specific application, but in general you have to ensure the proper procedure of castable work. Moreover if fallowing information is sheared it can help experts to suggest better.

• Castable type used.
• Procedure of castable work (vertical or horizontal).
• Dust circulation between cooler and kiln (high, normal, less).
• Burner pipe insertion inside kiln.
• Material buildup on burner tip (rhenohorn formation), and frequency of cleaning
• Fuel used, and appr. plume length.

Regards.

Bilalkkp.

Dear Sir ...

• you should check cooling air stream if there are any obstruct.
• you should do check for thikness to burner castable 
• you should do check for castable type and placing procedures
• do check to burner insertion length
• do check for Axial /Radial percentage .