Description

Rotary Kiln

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.

Main Features and Working Principle of Rotary Kilns:

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 firing pipe which acts like a large Bunsen burner. The fuel for this may be gas, oil or pulvierized coal.