Modeling and Box-Behnken design optimization of microwave treatment of sulphidic gold flotation tailing

As raw minerals become scarcer every passing day, the need for the recovery of mine tailings becomes essential. This research highlights the use of microwave energy as a green alternative to otherwise environmentally harmful methods of ore tailing recovery. The obtained results indicate that a 1.4 ppm Au and 3.5 % S sample floated with Aeroflot 208 and Aerophine 3418A increased the concentration of tailings over 18 % S and 4 ppm, Au, for recovery yield, resulting in 84 % and 80 % recovery, respectively. After microwave irradiation, 90 % of sulphur removal was reached under the optimum conditions of 50 minutes of irradiation using 1000 W for 4 g of the sample. Overall with 96. 74 % correlation of the quadratic model using the Box-Behnken design and expressed coefficient R2 regression the model was proven to be suitable for heating and roasting processes of gold-bearing tailings

Resource recovery as a sustainable perspective for the remediation of mining wastes: rehabilitation of the CMC mining waste site in Northern Cyprus

This paper highlights resource recovery and stabilization as the novel approach adopted in the rehabilitation strategy of the abandoned copper mine site (CMC mine) located in Northern Cyprus, recognized as a source of chronic pollution problems. The site holds 9.5 million tons of tailings stored in poorly equipped ponds. The waste contains pyrite and chalcopyrite undergoing slow oxidation this way, sulfide has been partly converted to sulfuric acid causing severe acid mine drainage problems. The rehabilitation strategy adopted the EU’s key principle of resource recovery, where all tailings would be processed for copper recovery and stabilized to further prevent the chemical mobility of heavy metals before final landfilling. A leaching-cementation process, with no chemical usage, except for lime stabilization after recovery, was designed for this purpose. The corresponding action plan entailed that all the waste material be processed in situ, in a zero waste environment. Accordingly, the remediation will be carried out in a sequential process involving emptying the ponds for resource recovery, preparing the necessary number of emptied ponds with sufficient holding capacity, as selected landfill sites in a way to secure and provide all necessary measures imposed by international regulations for containing and controlling hazardous wastes. Finally closure plans will be implemented for the rehabilitation of the mining site to reclaim full attributes of natural characteristics