Abstract

Mining is the most important economic activity in Chile, which is the largest copper exporterin the world. However, mining has significant environmental impacts, such as generatinglarge amounts of solid waste. Due to the high moisture content of solid waste, physicalstabilization problems can arise at disposal sites as a result of aqueous solutions trappedin solids not draining by gravity. Electroosmotic drainage has been proposed as a techniqueto reduce moisture and thus increase the stability of disposal sites. However, the questionarises whether the volume of drained solution depends on the percentage of fine matter inthe solid matrix. The experimental work reported here, based on an experimental factorialdesign, was carried out to address this question. The first part consists of an experimentaldesign with synthetic solid matrices. The percentage of fine particles and the initial moisturelevel were defined as factors with three levels. The volume of drained liquid was defined asthe response variable. The results showed that electroosmotic drainage was more efficientthan gravitational drainage when the moisture content and the percentage of fine materialwere at their highest levels. The effect of the factors and their interaction was corroboratedby an ANOVA. An equation was developed to describe the relationship between the responsevariables and the factors. Finally, considering the application of the technique in mining,tests were conducted on tailing samples and solid leaching residues. The tests showed thatthe technique is effective with tailings due to the high content of fine material and the initialmoisture level. However, it was not effective with leaching residues due to the low initialmoisture level and the low fine particle content.