It looks your raw meal composition is unsaturated in silica. Therefore, it is also aggressive to refractory products containing silica or silicates in their composition. Against to refractory problem and burning difficulties, you have to increase silica in raw meal composition. It is poosible to increase SM until 2,5 for raw meal.

Regards,

Dear Bazarah,

 Why don't you use an automized control of the burning process including a Burning Zone Measurement and Free Lime Prediction module.

I can guarantee you that your process stability will increase by 25%, with this you can control the free lime to your targets.

 If you want more information (and an article I wrote about this issue), please do not hesitate to contact me. alexander.hanf@powitec.de

Regards

Alex

Use our closed loop optimizer. We have a lot of experience with the described problem:

http://www.powitec.de/English/Cem_1_Overview_EN.html