In the present work, the potential of formation the AMD of tailings from Moatize (Mozambique) mine was evaluated by static methods (Standard Acid-Base Accounting, Modified Acid-Base Accounting, initial test of B.C. Research and NAG); and the quality of drainage water was monitored by kinetic methods (leach column - for 20 weeks and Soxhlet extractor - for 5 weeks). The chemical analysis of the sample by ICP-EOS showed the presence of total sulfur (S_total = 0,10%) and sulphate (SO₄^2- = 0,01%), which indicates the presence of pyrite (S_pyrite = S_total - SO₄^2- = 0,09%); while the mineralogical analysis by XRD revealed a predominance of the presence of acid-consuming minerals (silicates and carbonates). The obtained values of neutralization potential (NNP) for standard and modified ABA are 189,37 ton eq.CaCO₃/1000 ton and 163,44 ton eq.CaCO₃/1000 ton respectively; and the ratio of neutralization potential (RNP) corresponds to 61,6 and 59,11 respectively. The values of acidity potential (AP) and acidity consumption (AC) of the BC Research method are 3,067 kg H₂SO₄/ton and 6,37 kg H₂SO₄/ton respectively; whereas, the NAG method presented NAP value equal to 0,4 kg eq.CaCO₃/ton and pH equal to 5,47 ± 0,455. The statistical comparison of the results of standard and modified ABA methods, BC Research and NAG methods using the Minitab Software version 17, showed significant differences between the values obtained at a 95% confidence level, that is, although static methods showed the little risk of AMD formation from the sample, statistically the methods differ significantly from each other.  The kinetic tests were used to confirm the static results and, therefore, the determination of the AMD quality, where the physicochemical parameters (pH, Eh, CE and T) and metals (Mn, Zn, Cu, Pb, SO₄^2-, Fe²⁺, Fe³⁺ and Fe_total). The determined values showed that the sample has a small risk of AMD formation, which is an alert for the management of solid waste (tailings and sterile).

Keywords: acid rock drainage, tailings, pyrite, prediction, static and kinetic methods.