Environmental assessment and characterization of residues from coal processing and steel industry activities

Abstract

This work aims to characterize residues from coal processing and steel industry activities by means of physical–chemical analyses. The deposits were selected according to the field descriptions which aimed at the generic characterization of each deposit, mainly in relation to type/aspect and to the particle size range predominant in each deposit. Total extraction, as well as leaching and solubilization tests were applied to samples of coal waste, ash and residues from the steel industry. Results of the characterization indicated that the pollutant potential is more significant in coal waste than in ashes. Some metallic elements, such as Fe, showed high concentrations in the total extraction but they were not necessarily the most mobile when leaching and solubilization tests were conducted. Mn followed by Pb and Zn presented a more significant concentration in the extract of the tests mentioned earlier and a consequent higher mobility. The application of factor analysis to the variables studied emphasized the differences in the mobility of metallic elements regarding the tests used. These differences can be attributed to the association of metals to different mineral fractions (sulfides, carbonates and silicates) within coal.