Electroosmosis involves application of an electric voltage across a porous material to increase the hydraulic gradient, thereby speeding up fluid flow and hopefully consolidation, strength gain, and reduced permeability.

The paper The use of electroosmotic technique to improve safety conditions of abandoned tailings dams by Gross et al. tells of tests to see if electroosmosis could help consolidate tailings and make them less permeable. The work was undertaken as part of an evaluation of contamination control at abandoned mines in Sardinia, Italy. Here are their conclusions which pretty well summarize the paper:

The research presented in this paper concerns the study of the chemical and physical behavior of a mineral processing waste mud under the application of an electric field. It has been specifically aimed at evaluating the possibility of using electroosmotic process to induce fast consolidation in the tailing basin material. The experimental results demonstrate that, in the tested tail material, the electroosmotic flow can be induced without any chemicals addition. On the other hand, it increases from 0.05 cm3·cm-2·s-1 to 0.08 cm3·cm-2·s-1 by adding KCl salt in the electrolitycal solution. The electroosmotic permeability has been calculated and its value has been found to be in the range between 1.5·10-5cm2·V-1·s-1 and 2.5·10-5cm2·V-1·s-1. Furthermore, the comparison between electroosmotic and load consolidation, although under quite a restrictive hypothesis, shows that the electric field application drastically reduces the consolidation time. Finally, the electric energy consumption was calculated and it was evaluated to be economically acceptable.

This paper and a number of others have just been added to the InfoMine library courtesy of Raj Singal who gave us permission to choose and post our favorites from the CD of the proceedings of the conference he organized called Mine Planning and Equipment Selection and Environmental Issues and Waste Management in Energy and Mineral Production for the 2007 conference held in Bangkok, Thailand. The full CD is available through the InfoMine eStore.