Rotary kilns are designed to provide ultra-high temperature environments for conducting several thermal processing functions. These include drying, as well as high-temperature chemical transformations. Some of the most common reactions include:
Organic combustion
Heat setting
Calcination
Sintering and induration
Reduction roasting
Thermal desorption
Incineration
Probably the most common use for kilns in America is for the creation of raw concrete, by calcinating limestone at high temperatures.

Rotary Kiln Application

Alumina
Petroleum Coke
Zircon and Silica Foundry Sands
Catalysts
Kaolin and Bauxite Clays
Aggregates
Calcium Carbonate
Ore Concentrates
Titanium Oxide
Chromium Oxide
Ferrites

Fuels

Rotary kiln manufacturers have a wide variety of fuel choices, and kilns are often designed around the most optimal fuels for their desired use. Often, they’re simply heated by coal, but they could also use fuel oils, natural gas or propane, electricity, or synthetic heating gasses. They may also reuse their own waste heat for pre-heating materials.