Process for semi-wet treatment of flue gases including decarbonating water sprayed onto the flue gases

In a process for semi-wet treatment of flue gases to eliminate from them at least one polluting agent (HC1, SO2, HF), in which a mixture of whitewash from a first feed circuit, the flowrate in which is controlled depending on the measured quantity of polluting agent present in the flue gases at the outlet from the reactor, and industrial water from a second feed circuit, the flowrate in which is controlled depending on the measured temperature of the flue gases at the outlet from the reactor, is sprayed onto the flue gases to be treated in a reactor (1), the industrial water is decarbonated before it is mixed with the whitewash in an in-line tank in the industrial water feed circuit. The decarbonating treatment prevents clogging of the spray nozzles (10) of the reactor.