Contribution of the atmospheric emissions of Spanish ceramics industries

Contaminating industrial emissions produced by the ceramics industries (including frit and enamel production) can be divided into dust emissions and emissions produced in high temperature activities. Processes of accumulation and precipitation on the substratum, of compounds enriched in certain elements used in this type of industry can occur. The objective of the present work was to identify the contribution of the emissions of the ceramics industries to the atmospheric particulate that is susceptible to depositing on vegetation and accumulating in the substratum. Samples obtained from high volume collectors were studied. Two zones were considered: zone A, a high volume collector located in the municipalities adjacent to the companies that were the object of the study; and zone B, a high volume collector further away from the said companies and adjacent to a power station and a refinery. The analysis techniques were X-ray diffraction, scanning electron microscopy (SEM), and ICP-MS. The results obtained by means of the X-ray diffraction technique showed a high percentage of clays in the samples, minerals used as raw materials (K-Ba feldspar, zircon silicate), indications of high temperature phases, as well as a background noise characteristic of material of low crystallinity. The SEM analysis confirmed the presence of vitreous particles, which are crystalline phases at high temperature typical of the production of a large variety of frits. The results obtained in the chemical analysis demonstrate that (a) the influence of the frits and enamel production on the high concentrations of Zr, Cu and Ce obtained in zone type A compared with zone B; (b) the affect of clays used as raw materials in the ceramics industry can be demonstrated by the high concentrations of Fe, Al and Mg. The weekly evolution showed two series of elements, a characteristic group of dust emissions and another group of tracers from high temperature processes.