PROCESS OF DECREASING NOX CONTENT OF EXHAUST GASES

摘要

For a decrease of NOx content in the exhaust gases from cement-burning kilns by an addition of ammonia and/or ammonia-containing substances to hot exhaust gases, the exhaust gases are desulfurized at a temperature from 50 DEG to 100 DEG C. in a dry or semidry process by a mixture of raw cement powder and calcium hydroxide, and the mixed solids which have been removed the exhaust gas in a dry state in the desulfurizing stage are returned to the exhaust gas stream when it is at a temperature from 850 DEG to 1,000 DEG C.