Abstract: The invention relates to a method for heat treatment of fine calcium carbonate bearing material comprising preheating fine material containing a coarse and a fine fraction. The preheated material is delivered into a fluidized bed calcining means wherein the coarse fraction is calcined and the fine fraction is delivered by process air to an adjacent vertically arranged gas flash calciner furnace in which it is calcined.

Abstract: An integrated process blending apparatus which blends particulate material and also automatically controls the flow of material into the blender and out to the associated processing equipment. Load cells attached to the blender vessel are used to control the entry of material into the blender, while the pressure drop in the blender output pipe is used to control an output deflector to either remove or recycle material within the blender. The blender is also made more effective by dividing it into vertical compartments with separators which have angled portions preferably in their lower regions to cause different downward flow velocities in each compartment, and by creating a multistage blender by stacking sets of offset compartments one on top of another.