Electrokinetic remediation of copper mine tailings
Sustainable process-product development & green chemistry
Sustainable & Clean Technologies - Ia: Extraction & Remediation (T1-4a)
Keywords: electric current, copper removal, pulsed electric field, ion exchange membranes
The heavy metal contamination from mining industry has become a growing problem both in Chile and worldwide. This contamination includes large areas with soil pollution, contaminated rivers and continuous generation of mining waste deposits. The solid waste that will be analysed is mine tailings, which are the residual products after the flotation process in conventional sulfide copper mining. These tailings are known to contain considerable amounts of different heavy metals. Today the mine tailings are deposited directly on areas close to the mine without any controlled pretreatment or ground and surface water protection.
This work consists of series of electrochemical remediation experiments using an electric field as remediation agent in order to remove/concentrate heavy metals (specially copper) in a way that minimises the volume of contaminated matter significantly. During the experiments several parameters are monitored such as current density, voltage drop, pH in the soil/waste, metal mobility and removal rate. Adjustable parameters are current density, water content, distance between electrodes and remediation time. Furthermore, the remediation process can be optimised with the use of ion exchange membranes, which also is included in the experimental part of this project. Other parameters that will be discussed in this work are: the use of pulsed direct current, addition of dissolving or complexing agents, and use of different electrolyte solutions.
It was found that electrochemical remediation of mine tailings and soil contaminated from mining industry could be an alternative to depositing the waste. To positive aspects are generated by this remediation technology: 1) an environmental friendly solid waste without elevated concentrations of metals, 2) a profit consisting of dissolved copper that can be used directly in the copper refinery proces meaning that natural copper containing minerals can be saved, and 3) a possible tool to recover copper from minerals with low grade.
Presented Wednesday 19, 11:18 to 11:36, in session Sustainable & Clean Technologies - Ia:Extraction-Remediation (T1-4a).
