In a strictly scientific sense “calcining” is the process of decomposition of calcium based materials such as Calcium Carbonate (Limestone) using heat. Even today the most common “calciner” is a lime kiln where limestone is heated, driving off carbon dioxide to produce calcium oxide – “lime”. Over time the term calcination has become more general and implies the use of heat to bring about chemical change. Lime kilns, shaft furnaces, rotary kilns and fluidized bed reactors can all be called calciners. Apart from lime and cement manufacture calciners are also used for processing bauxite, gypsum and petroleum coke. In all cases a hot dust laden gas stream must be cleaned prior to discharge, usually up a tall chimney. In the past, electrostatic precipitate were a preferred choice because of their ability to work at high temperature but ever tighter emission standards means that bag filters are now used most often. The AAF FabriPulse XLC with its off-line cleaning and on-line maintenance facility is ideal for a calciner exhaust especially since continuous operation is required for long periods without a shut down.