Pretreatment of aqueous phase of mine plant tailings for submarine disposal

Abstract

Submarine disposal of mine tailings is a relatively recent technology that holds the promise of solving the recurring problems that the mining industry has had with tailings disposal. The system has been successfully implemented in many mines around the world. Before implementation, however, a decision needs to be made whether the biogeochemical characteristics of the area selected for submarine disposal and characteristics of the tailings are conducive to implement submarine disposal of tailings. While an expert system can decide the feasibility of submarine tailings disposal (STD) based on its database of information and decision loops for the critical factors, tailings cannot be disposed of under water without pretreatment, which is the focus of this thesis. Bioremediation, freeze concentration and reverse osmosis were examined as possible alternatives for treatment. Laboratory tests were performed for all the methods, and in the case of bioremediation, pilot scale tests were also performed. It was concluded that all the three methods remove dissolved metals from mine water to varying degrees. Reverse osmosis was found to be the most efficient method, while freeze concentration was the least efficient method.