Evaluation of mineralogical changes of sediments affected by Dar-e-Allo copper mine, south of Kerman: application for environmental studies

The present study has been performed to evaluate the prospective effects of activity mining on the mineralogy of sediments in the Dar-e-Allo copper mine, south of Kerman. Sediments affected by Dar-e-Allo mine are divided into six sedimentary groups including: natural background sediments, sediments of waterways leading to the mine, sediments of the Sarmashk River, sediments under the waste rock dump, sediments containing secondary phases, Fe-Mg oxy-hydroxide sediments, and evaporative sediments. Mineralogical studies of sediments as an indicator to evaluate the environmental effects of mining are classified into five main groups including primary and unaltered, carbonate, clay, sulfate and oxide minerals. Sediments in the operational area of the Dar-e-Allo copper mine are associated with extreme mineralogical diversity. The sulphide minerals are the most important source of acid mine drainage and secondary minerals such as gypsum, starkeyite, copiapite, magnesiocopiapite and natrojarosite are the most important temporary reserves of potentially toxic elements (PTEs) and H+ ions. The dissolution of the mentioned minerals, especially during the initial flushing events in the wet season, cause a sharp increase in the acidity and concentration of PTEs in the surface runoff.