Patent ID: 7044996

Claim:
A method for reducing and removing a build-up forming on a floor grate of a fluidized bed furnace in roasting of a fine-grained material, the method comprising: feeding the material into a roaster from a wall of the furnace at a feed point; feeding oxygen-containing gas via gas nozzles situated under the floor grate in the bottom of the furnace in order to fluidize and oxidize the material; increasing an oxygen content of the gas fed through a feed grate portion of the floor grate, which is near the feed point of the material, compared to an oxygen content of gas fed to a remainder of the floor grate; and providing a plurality of gas nozzles in the floor grate in a concentration, per unit area, such that the concentration of nozzles in the feed grate is between 5% and 20% greater than a concentration of gas nozzles in the remainder of the floor grate, all of the gas nozzles being connected to a single gas feed tube.