USE OF STEEL SLAG TO NEUTRALIZE ACID MINE DRAINAGE (AMD) IN SULFIDIC MATERIAL FROM A URANIUM MINE

Acid Mine Drainage (AMD) is one of the main environmental impacts caused by mining. Thus, innovative mitigation strategies should be exploited to neutralize acidity and prevent mobilization of trace elements in AMD. The objective of this study was to evaluate the use of steel slag to mitigate acid mine drainage in sulfidic material from a uranium mine, as an alternative to limestone. Increasing doses of two neutralizing agents were applied to sulfidic material from the Osamu Utsumi uranium mine in Caldas, Minas Gerais State. A steel slag from ArcelorMittal Tubarão and commercial limestone were used. The experiment was conducted in leaching columns arranged in a fully randomized factorial design with two neutralizing agents, three doses, and one control, totaling 21 experimental units. Electrical conductivity (EC), pH, and concentrations of various trace elements were evaluated in leached solutions. The results indicated an increase in pH for both agents, with steel slag performing slightly better. Lower EC was noted at the higher limestone dose, and CO2 emissions were greater with limestone compared to steel slag. The study concludes that steel slag is a suitable alternative for mitigating AMD while reducing CO2 emissions compared to limestone.