PROCEDE DE TRAITEMENT THERMIQUE DE MATIERES EN GRAINS FINS

摘要

Fine-grained material, such as lime, dolomite and magnesite, is subjected to a thermic treatment in suspension in a hot gas stream and the desired product is subsequently separated in a separator. A vertically disposed treatment chamber is divided into two vertical parallel reaction zones and is connected at its lower end with a hot gas producer whose hot gases pass through the treatment zones and into separator. The material to be treated is so introduced into the treatment chamber that the coarser fraction of the material drops in one of the reaction zones into an upstream of the hot gas having a relatively low velocity while subsequently in the other reaction zone the material is caused to flow with increased velocity and then into the separator. The exhaust gas leaving the separator is conducted to a preheater, preferably a multistage cyclone heat exchanger, and the dust discharge conduit of the latter is connected with one of the two reaction zones of the treatment zone. The treated material which leaves the separator is cooled and the extracted heat is conducted to the hot gas producer as additional combustion air.