(10)Solvent extraction for separation of metals from hev Li-ion batteries nitrate leach liquor

摘要

Hybrid electric vehicles (HEVs) are gaining popularity as one of the moreeconomic choices for transportation. The Li-ion batteries with varyingchemistries are one of the favored batteries for these vehicles. The growingnumbers of HEVs will soon result in a large number of end-of-life batteriesin next decade. Currently there is little infrastructure to handle or recycleend-of-life Li-ion batteries. The economic incentive for recycling will also besoon lost as new chemistries are replacing the conventional cobaltchemistries with other cheaper metals. However, recycling whenunderstood from a cumulative reasoning such as resource re-use andreducing environmental load caused due to virgin metal extraction whichinvolves mining, transportation, processing emissions and load because ofimproper waste management of end of life batteries. The Li-ion battery hasmetals such as Li, Fe, Co, Ni, and Mn, which are in the black mass i.e., andare the electrochemically active fraction of the batteries. Additionally thecurrent collectors are made of Al and Cu. After dismantling, heattreatment,and mechanical separation, the black mass is separated fromthe current collectors. This black mass was then leached off its metalsusing 1 M HNO3. Solvent extraction was chosen to achieve separation andrecovery of metals from this leachate with high purity.In the current article, a screening study for the separation of Li(I), Ni(II),Mn(II),Co(II), Fe(III) from nitrate leachate using both acidic and solvatingextractants was made. Solvent extraction studies were done using anAKUFVE unit. The separation studies that were made with acidic extractantwere made with respect to pH and extractant concentration and studieswith solvating extractant were made with respect to nitrate concentrationand extractant concentration.