CHEMICAL AND PHYSICAL PROPERTIES OF POLISH COAL ASH.

This research was done in order to study the fundamental effects of chemical and physical properties of coal ash on a sulfuric acid leaching process. The sample of coal ash from Poland has been examined by photomicroscopic observation, and passed through electron microprobe analysis, spectro graphic analysis, quantitative analysis, size separation, X-ray diffraction, thermal gravimetric analysis and differential thermal analysis. The main results obtained are summarized as follows: The major elemental constituents of coal ash are Si, Al and Fe, together with minor amounts of Ca, Mg, Na, Ti, C and S. The mineral content of coal ash are primarily mullite (3Al//2O//3-2SiO//2), with the presence of hematite (Fe//2O//3), magnetite (Fe//3O//4) and silica (SiO//2). The results should be useful in recovering the metals which are contained in a coal ash using a sulfuric acid leaching process.