In the present work six flotation tailings impoundments at five flotation plants (Piuquenes, Cauquenes, El Salvador, Ojancos, P. Cerda) located in different climatic zones of Chile were selected to investigate the mineralogical and geochemical changes taking place in copper flotation tailings subsequent to sulfide oxidation, especially the formation of acid mine drainage and element mobility. Results show the importance of primary mineralogy (acid producing and acid neutralizing minerals) in controlling the mobility of the liberated elements due to pH control. Climatic conditions control the element mobilization directions (humid = downwards; arid = upwards) and so the geochemical conditions where these elements may precipitate as secondary minerals (humid = reducing conditions below the water table; arid = oxidizing conditions at the surface). The climate controls so the secondary mineralogy and thus the availability of hazardous heavy metals to the environment. Additionally the impoundment construction technique may influence the mobilization and enrichment processes.