Method for controlling the oxidation and calcination of waste foundry sands

摘要

The waste sands are passed to a calcining chamber having a floor, connecting sidewalls and a top. The floor of the calcining chambers provided with a plurality of vents. The calcining chambers also connected to a separate firebox which produces fluidizing hot gases for fluidizing waste sands within the calcining chamber and forming a fluidized sand bed. The fluidizing hot gases are introduced into the calcining chamber by means of the floor vents. By precisely controlling the temperature of the waste sands within the fluidized bed, a more consistent product is produced while maintaining the temperature of the waste sands below a critical temperature at which the organic binders present on the sand grains would be fused to the waste sand grains.