Abstract
The impact of airborne pollution by slag from magnesium production was analyzed under different climate conditions. The slag is characterized by X-ray diffraction analysis, scanning electron microscopy, differential thermal analysis and atomic absorption analysis. The dominant phase was the γ modification of dicalcium silicate (γ-2CaO SiO2) with significant amounts of perclas (MgO), gehlenite - 2CaO Al2O3 SiO2, akermanite - 2CaO MgO 2SiO2 and portlandite Ca(OH)2. The granulometric composition of the slag was within the range of 100 x 10-3÷0.090 x 10-3 m. Ad hoc measurements were performed on site in June at 300 and 600 m distance from the slag deposit, which showed high Total Suspended Particles (TSP) concentrations. Imputing the results of an experimental investigation of the dust emission for wind velocities of 5, 7, and 10 m/s and within the range of relative humidity from 10÷50% into SCREENVIEW software, the obtained values on the diagram showed good agreement with those of measurements on site. The simulation, that considered the landscape and wind increases over a 20 year period, showed that the dust concentration will be over the Maximum Allowable Concentration (MAC) up to 1400 m from the deposit, for an average wind speed of 3.0 m/s, a relative humidity of 37% and up to 4000 m under unstable weather conditions.