Fluorine compounds in gaseous emission from industrial sources: the case of ceramic industries

This paper assesses fluorine emissions as atmospheric pollutant originated from the clay-based raw material used in ceramic industries. After a short review on production technology of ceramic products, the main features of fluorine emission during firing processes are outlined. It is demonstrated that the emission rate of fluorine increases with the increasing fluorine content in the raw material and the firing temperature. It’s reported a roundup of methods for emission sampling and analysis of fluorine content both in gaseous emission and in clay raw materials. The fluorine content of clays on average are much the same as the typically found in the Earth’crust, as different studies reported in this work have shown, and hence clays cannot be considered a great source of fluoride. However due to the large amount of clays used, the total emission needs to be under control: detailed review of principal abatment techniques, usually used in the ceramic sector, are described, in order to underline the different abatment efficiency. A very brief summary of diseases caused to animals and plants by an excess of fluoride in water an atmosphere is also presented.