Electrokinetic Treatment Affected by EDTA and Applied Voltage Drop for Cu Mine Tailings
Deng Chang · 2005
The effect of application EDTA as enhanced reagent and applying different voltage drop on the copper electrokinetic processes in a Cu mine tailingswas examined. The results showed that EDTA, added in the catholyte, decreased the electric currents, but increased the electroosmotic flows due to its low electroconductivity and dissolution of mine tailings. Soil pH values after electrokinetic treatments varied with the addition of various concentrations of EDTA. When EDTA concentrations were above 1.0 mmol·L-1, the pH values of mine tailings were higher than that of mine tailings without electrokinetic treatment. Copper removal percentages in Exp-01 to 04 after electrokinetic treatments were 19.6 %, 18.3 %, 31.5 %and 37.2 %, respectively. It was only 3.2 %for the treatment without application of voltage gradient. When a voltage drop of 30 Vwas applied in the electrokinetic setup, the removal rate of Cu from the mine tailings was 43.8 %. These indicated that application of EDTA and high voltage drop increased the removal rate of Cu from the Cu mine tailings, and electrokinetic treatment with a longer duration improved the removal percentage of Cu.