Electroosmosis of gold tailings under multiple electrokinetic geosynthetics electrodes

Abstract

In dry-stack tailing ponds with high fine-grained content, a high long-term saturation line can lead to dam failure. Electroosmotic consolidation is an effective method for reducing dam saturation lines. However, traditional electrodes have low corrosion resistance and poor contact, which limits the development of electroosmotic drainage technology for tailings. In this study, an electroosmotic drainage device, an electrokinetic geosynthetic (EKG) electrode, was designed. The influence law of the electrode material, potential gradient, and number of electrodes on the water drainage, current, and resistance was analyzed. The results show that the EKG electrode has excellent corrosion resistance, with its weight loss after electroosmosis, water drainage, and equivalent allowable current being 1.67%, 122%, and ∼2.3 times that of a copper electrode, respectively. Furthermore, it was found that the optimal potential gradient was 1.2 V/cm, and the water drainage cannot be improved by an exceedingly high potential gradient. The current pathway in the test box was in parallel, and the water drainage increased to 410% and the contact resistance decreased by 83% when the number of electrodes was four. These results and novel methodology provide new ideas for EKG electrode design and represent an effective method for saturation line control in gold tailing ponds.