Enhancement of the sedimentation rate of copper tailings by application of acoustic fields

Abstract

The rate of sedimentation in tailings thickeners in the mining industry is negatively affected when ultra-fineparticles like clays or over-grinded particles appear in the concentration process. Such particles, sized less than50 μm, reduce speed severely thus generating sedimentation suspensions. This harmful effect must be compensatedwith a reduction in the feeding rate, putting the entire upstream operation at risk. In the present study,results of the application of transversal and longitudinal ultrasound waves are shown in the sedimentation oftailings from copper mining to establish if the process can be accelerated. For this purpose, a rotating sedimentationsystem was designed and manufactured. It included sedimentation tubes equipped with electroacoustictransducers to stimulate the system in various ways during the sedimentation process. Different sedimentationexperiments were developed to evaluate the effect of the excitation frequency and the position of thetransducers. In each experiment, the copper tailings sample was mixed in the tube with anionic flocculant andsubjected to ultrasonic fields with different frequencies to determine the tailings samples’ settling characteristics.It was found that the applied ultrasonic treatment positively affected the tailings processing and improved thespeed of sedimentation.