Rotary
kiln is a pyroprocessing device and used to raise materials to a
high temperature(calcinations)in a continuous process.Material
produced using rotary kilns
include:cement,lime,refractories,metakaokin,titanium
dioxide,alumina,vermiculite.They are also used for roasting a wide
variety of sulfide ores prior to metal extraction.
The kiln is a cylindrical vessel,inclined slightly to the
horizontal,which is rotated slowly about its axis.The material to
be processed is fed into the upper end of the cylinder.As the kiln
rotates,material gradually moves down towards the lower end,and may
undergo a certain amount of stirring and mixing.Hot gases pass
along the kiln,sometimes in the same direction as the process
material(co-current),but usually in the opposite
direction(counter-current).The hot gases maybe generated in an
external furnace,or may be generated by a flame inside the
kiln.Such as flame is projected from a burner-pipe(or
