Pyroprocessing in the context of Sintering

A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Kilns have been used for millennia to turn objects made from clay into pottery, tiles and bricks. Various industries use rotary kilns for pyroprocessing (to calcinate ores, such as limestone to lime for cement) and to transform many other materials.

A rotary kiln is a pyroprocessing device used to raise materials to a high temperature (calcination) in a continuous process. Materials produced using rotary kilns include:

• Cement
• Lime
• Refractories
• Metakaolin
• Titanium dioxide
• Alumina
• Vermiculite
• Iron ore pellets
• Incineration of biomedical waste
• process like pyrolysis {with without passing hot gases}

They are also used for roasting a wide variety of sulfide ores prior to metal extraction.

Cement kilns are mechanical, industrial furnace used for the pyroprocessing stage of manufacture of portland and other types of hydraulic cement. The kilns use high heat to cook calcium carbonate with silica-bearing minerals to create the more reactive mixture of calcium silicates, called clinker, which is ground into a fine powder that is the main component of cements and concretes.

Kilns are relatively distributed technologies all over the world: over a billion tonnes of cement are made per year, and cement kiln capacity defines the capacity of the cement plants. The kilns is an integrated part of the cement plant, connected by a number of ancillary pieces of equipment, used to engineer an ideal flow of cement to the rest of the system. Improvement to kiln systems and ancillary equipment, such as heat recovery, can improve the efficiency kilns and reduce the cost of overall operation of a cement plan.