I would like to raise question with regard to the impact of strontium (Sr) to EP efficiency. From our experience, there is a negative correlation between Sr concentration to EP efficiency. When Sr increased, dust emission increased too. Our Sr content in limestone rock varies from 183 to 1382mg/kg. Or, do you suspect from another elements such as organic matters as well as high dust resistivity, too?

Your experience with strontium is very interesting and I have not heard of it before. The performance of your ESP will also be affected by organic matter and the resistivity of the dust. The key question then becomes are these variables independent of one-another? I know of no reason why strontium would increase the resistivity of the dust.

We've been faced with a problem that the collecting efficiency of the electrostatic precipitators lowers remarkably since having started to use sewage sludge as the secondary material. I'm not sure where the cause is from. Is there any possibility of causing such problem by using sewage sludge, and which kind of components that sewage contains can affect the performance of ESP? As the reference, we've been experienced in the same problem when we used TPA sludge(Telephtalic Acid) two years ago.

I have not heard of this phenomenon before. The resistivity of the dust exiting the preheater must be changed when burning these sludges. I hope all the sewage sludge is being burnt in the kiln and the problem is not caused by organic residues entering the ESP. If so then the problem can only be associated with volatiles derived from the sludge entering the ESP with the dust. The most likely source is chlorides from the sludge. You should also check carefully that the problem is not caused by mercury from the sludge. If so then you have a big problem.