EN
We researched industrial wood ash in order to assess its posed threats and possible applications. The ash is type S; due to the content of SiO₂, CaO, Al₂O₃, Kb>2O, Fe₂O₃, Na₂O, MgO, SO₃, and TiO2 it is alkaline (pH = 12.9) with small bulk density (<1.4 g/mL); and it is characterized by high fragmentation and irregularly shaped grains (research SEM/EDS). It has a high cationic-exchange capacity (56 mmol/100 g) and a negatively-charged surface (pH>pHPZC), which suggests the possibility of sorption cations. Research of the structure of phases present in the ash (FT-IR method) and physical or chemical changes with their accompanied thermal effects in the temperature range 25-900º (TG/DTG method) indicate no degradation of aluminum-silicon skeletons. Metals occur inside and in the surface layer of the grain (FAAS, SEM/EDS analyses). Research of fractionation of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn (classic Tessier’s method) indicated high mobility among others (Co 28.44%, Cr 20.49%, and Pb 16.51%), which poses a risk of environmental pollution. The obtained results indicate 2 directions of ash application: (i) limited environmental due to heavy metal and (ii) processing in geopolymer.