Abstract: The thermal treatment is effected in that hot gases are passed through the charge bed. Hot gases are passed downwardly through the charge bed in heat treating zone, oxygen-containing cooling gases are passed upwardly through the charge bed in a cooling zone, and the cooling gases which have been heated are conducted under a continuous gas hood from the cooling zone into the heat treating zone.

Abstract: An improved process for heat-treating pellets in a pelletizing machine in which hot gases are generated and passed through a bed of pellets includes charging solid carbonaceous fuel onto the surface of the pellet bed and burning the carbonaceous fuel to generate at least a portion of the hot gases.

Abstract: A process for the ignition of sinter mixtures containing solid fuels and apparatus for carrying out this process. The ignition is effected by means of hot combustion gases which are produced, under certain specified conditions, by the combustion of gaseous or liquid fuel initially in a swirl combustion chamber and then under a hood from where they are suctioned through the sinter mix.

Abstract: A process for measuring, optimizing and controlling the gas permeability of a sinter mixture on a travelling grate by adjusting the flow of air and/or fuel to the furnace to maintain a zero pressure differential between the inside and the outside thereof such that all the gas generated permeates the sinter mixture, and determining the gas permeability as a function of said flows. These steps are repeated for various values of selected process parameters having a significant influence on gas permeability, one at a time, in order to determine the value of each parameter which produces optimum gas flow.