Rotary waste incinerators typically consist of a rotating cylinder and a secondary combustion chamber (SCC). The rotary unit is used to volatilize the waste fed into it and to render the solid residue benign to the environment. Solids, sludges, slurries, liquids, and packaged wastes can all be incinerated in a rotary unit. Rotary incinerators may further be classified as either ashing or slagging depending upon the temperatures at which they operate. Residues exiting the rotary can include ash, molten slag, frozen slag, and uncombusted solids such as ferrous metals and glass. The gases and some fly ash generated in the rotary kiln are transported to the SCC, where final thermal destruction of the waste is achieved by adding oxygen to the system or by use of an auxiliary burner.