Method for preheating cement clinker raw materials

摘要

A method is disclosed for heat treating raw material components of a cement clinker prior to admitting the components to a reactor for sintering the components to form the clinker. A calcareous component of the raw material is preheated with a hot gas flow and admitted to a furnace in a calcining stage. Fuel combusted in the furnace heats the calcareous component to a calcination reaction temperature and calcines the component. The calcined component is transferred to a furnace in a superheating stage where a fuel is combusted to further heat the component beyond a sintering temperature at which a calcined component and an argillaceous component sinter to form cement clinker. The superheated calcareous component is transferred to a sintering reactor. Hot gas from the furnace in the sintering stage is passed to the furnace in the calcining stage to augment the heat in the calcining stage furnace. A flow of hot air from a cement cooler is passed to a second exchanger to preheat and dehydrate an argillaceous component of the raw material. The dehydrated argillaceous component is transferred to the sintering reactor and sintered with the superheated calcareous component with the sensible heat of the calcareous component supplementing the heat needed to maintain sintering and the reactor providing only the heat as needed to augment the heat of the calcareous component.