화학공학소재연구정보센터
Journal of Hazardous Materials, Vol.341, 297-303, 2018
A novel polymer inclusion membrane based method for continuous clean-up of thiocyanate from gold mine tailings water
Thiocyanate is present in gold mine tailings waters in concentrations up to 1000 mg L-1 and this has a serious environmental impact by not allowing water reuse in the flotation of gold ore. This significantly increases the consumption of fresh water and the amount of wastewater discharged in tailings dams. At the same time thiocyanate in tailings waters often leads to groundwater contamination. A novel continuous membrane-based method for the complete clean-up of thiocyanate in concentrations as high as 1000 mg L-1 from its aqueous solutions has been developed. It employs a flat sheet polymer inclusion membrane (PIM) of composition 70 wt% PVC, 20 wt% Aliquat 336 and 1 0 wt% 1-tetradecanol which separates counter-current streams of a feed thiocyanate solution and a 1 M NaNO3 receiving solution. The PIM-based system has been operated continuously for 45 days with 99% separation efficiency. The volume of the receiving solution has been drastically reduced by recirculating it and continuously removing thiocyanate by precipitating it with in-situ generated Cu(I). The newly developed PIM-based thiocyanate clean-up method is environmentally friendly in terms of reagent use and inexpensive with respect to both equipment and running costs. (C) 2017 Elsevier B.V. All rights reserved.