(JP4505361-W)      Wastes, biological sludges or metal oxide concentrates contg. halogenated hydrocarbons are treated at a high temp. and the gases formed are cooled to minimise the amt. of polyhalogenated environmentally harmful cpds. emitted. The materials to be treated are first heated or burnt in O2-contg. gas to decompose the halogenated hydrocarbons. They are then cooled at 300 deg.C or more per second from 400 deg.C to below 250 deg.C which prevents the halogenated hydrocarbons being reformed.    Pref. the gases are cooled in a circulating fluidised bed reactor using a large amt. of particles for cooling the gases rapidly and then recycling particles sepd. from the cooled gas. The particles are cooled before they are sepd. from the gas or after sepn. Combusting is at 830-1000 deg.C or over 1000 deg.C, esp. on a grate. Gas cooling to over 400 deg.C is in a waste heat boiler. An S-absorbing material recovers S cpds. in the form or a second fluidised bed reactor. The flue gases are cooled at over 1000 deg.C.    USE -   Process prevents emission of suspensions such as coplanar PCB, polychlorinated dioxins and polychlorinated furans    (EP472567-B1)      A method of treating various materials, such as wastes, biological sludges or metal oxide concentrates, which materials contain halogenated hydrocarbon compounds, at a high temperature and of cooling resultant process gases for minimising the amount of polyhalogenated compounds harmful to the environment, such as dioxins and furans, in the emissions of combustion processes, wherein the materials to be treated are first heated or combusted in the presence of gas containing oxygen in a circulating fluidised bed boiler at 830-1000 deg.C for combusting the material and for decomposing polyhalogenated compounds present in the material, the process gases thereby resulting are cooled with a cooling velocity of at least 300 deg. C per second past the temperature range of 250 to 400 deg. C in a circulating fluidised bed reactor.    (US5481063-A)      A method of treating heterogeneous combustible material which contains halogenated hydrocarbon cpds., comprising the steps of:    (a) combusting the material under conditions and at a temp. sufficient to decompose polyhalogenated cpds. in the material, producing flue gases contg. cpds. capable of forming dioxins and furans; and    (b) rapidly cooling the flue gases through the temp. range of 250-400 C, to below 250 C, to prevent the formation of dioxins and furans in the flue gases.