Relation between chemical treatments and defect structure of calcium carbonates in industrial ashes

In incineration processes, chemically treated industrial residues (ashes) a re generally composed of carbonates, sulfates, and silicates as major compo nents. However, following the nature of chemical treatments, each major pha se may present various structural defects or retain various pollutant eleme nts. To try to correlate such defects to the chemical processes, four types of ashes corresponding to four different treatments have been selected. A careful analysis of the calcium carbonate phase is presented. Using scannin g electron microscopy and X-ray diffraction analyses, some correlations bet ween the X-ray diffraction data and the corresponding treatments are discus sed. Using diffraction profile analysis, we propose a method correlating th e defect structure of each sample with the treatment process. (C) 2000 Else vier Science Ltd. All rights reserved.