Abstract: The invention relates to a process and an installation for the treatment of gaseous effluents produced by at least one electrolytic cell (1) in which the effluents are conveyed by at least one conveyance duct (11) to treatment means (12-19) comprising at least one reactor (12) to extract fluorinated products contained in effluents by reaction with powder alumina (16) and a separation device (13) to separate the alumina output from the reactor (12) from the residual gas fraction and comprising filter means (14). According to the invention, the effluents are cooled before being treated by the injection of droplets of a cooling fluid into the conveyance duct(s) (11) at at least one point (P) located upstream of the reactor (12), and by vaporisation of the said fluid. The invention provides an efficient means of cooling effluents from electrolytic cells without affecting their operation.