According to different calcination methods, bauxite has the difference between rotary kiln and shaft kiln.

The bauxite calcined in the shaft kiln is evenly heated, has a high density, and has a relatively objective output; it is calcined by burning coal.

Rotary kiln calcined bauxite is relatively non-uniform in heating and low in density; it is calcined with coal powder, heavy oil, and gas fuel.

The two can be clearly distinguished from the appearance, and the latter is whitish in color.