Hello Ammar,
There are really only two practical ways to eliminate a detached plume;- either eliminate the source of ammonia, chloride or SO2 in the raw materials (particularly organic matter and sulphides such as pyrites), or eliminate the acidic components which form
ammonium salts in the kiln gases before they leave the stack. (ie HCl and SO2)
Eliminating the source of ammonia, chloride or sulphides in the raw materials is not always possible, since selectively mining raw materials can be a very costly option. Therefore, eliminating the acidic omponents which form ammonium salts before they escape
out of the stack is usually the preferred option.
As Al Linero mentioned above, the cheapest way of doing this is to inject a fine mist of filtered lime slurry into the conditioning tower whenever the raw mill is shut down. Lime will not remove the ammonia, however it will react with any chloride or SO2
in the kiln gases to form solid calcium chlorides and calcium sulphates which prevent the chloride and SO2 from reacting with ammonia.
Once the raw mill is started again the lime sprays can be turned off since the incoming raw meal will absorb the ammonium salts and prevent them leaving via the stack.
One more thing... do you use ammonia to control NOx emissions (ie SNCR)? If so, the phenomenon of "ammonia slip" (unreacted ammonia in the stack gases) may be the cause of a detached plume.
Regards,
Ted.
