Characterization of a coal tailing deposit for integrated mine waste management in the brazilian coal field of Santa Catarina

Brazilian coals contain high levels of impurities (pyrite and sedimentary rocks minerals), requiring concentration procedures. The coal tailing deposits demand a large physical area, whose topography is changed and acid mine drainage (AMD) is generated. The aim of this work was to characterize a typical coal tailing deposit in the carboniferous region of Santa Catarina, seeking the separation of three fractions for future reuse: (a) a fraction for energy production; (b) a fraction composed mainly by silicate minerals; and (c) a fraction with a high concentration of pyrite. The work methodology consisted in sample collection and characterization of the material. The characterization included particle size analysis, dissymmetric studies, XRD analysis, petrography studies, and acid-base accounting tests. The results showed that 68% of the material is composed of coarse particles, 15% of fine particles, and 17% of slurry from settling ponds. It is possible, by gravimetric concentration of the material, to recover 33.7% for energetic application and 10.3% as a pyrite concentrate. The remaining material, with intermediate density, will have a decrease of about 60% in its net acid generation potential and presents potential for application in civil engineering construction.