An environmental oriented model for optimum cut off grades in open pit mining projects to minimize acid mine drainage

Environmental concerns on mining activities started near the end of the 20th century and is still underway. Due to mining activities, the adverse environmental impact has been significant throughout the history of mankind, whereas the minerals produced by mining activities have been providing the basis for human civilization. The legacy of past mining practices is large quantities of acid generating waste materials and tailings that caused abounding acid mine drainage problems. Modern mining environmental management tends to focus on concerns over the impact of waste disposal on surface primarily in the form of tailings and waste materials structures. Sustainable development principles are being increasingly applied by mining companies in developed and developing countries. Operating costs per unit of operation is recognized to be one the most important sustainable mining practice indicator and cut off grade is considered to be a well-founded representative for this indicator. In this paper, a developed model for optimum cut off grades is presented that not only relies on economical aspects but also minimizes adverse environmental impact in the form of acid mine drainage elimination or mitigation against the approach of postponing the restoration/reclamation activities at the end of the project's life.