Described is a method as well as a plant for preheating particulate or
pulverulent material such as cement raw meal or similar material in a
cyclone preheater (1), comprising at least two cyclone stages, each
comprising a riser duct (2a, 2b, 2c, 2d) and a cyclone (1a, 1b, 1c, 1d).
The method is peculiar in that a portion of the material which is fed to
at least one cyclone stage is introduced to the first part of the riser
duct, viewed in the direction of travel of the exhaust gases, and is
heated from a temperature of maximum 450.degree. C. to a temperature of
at least 550.degree. C., and in that the remaining material which is fed
to the same cyclone stage is introduced into the last part of the said
riser duct. As a result, there will be a reduction in the amount of
SO.sub.2 which is discharged from the cement plant preheater as emission,
without a simultaneous increase in energy consumption.