Research On Recovery Copper Based On Electrolysis With Ionic Liquid From Waste Mobile Boards

With the economic and social development,electronic product update cycle shortened,represented by waste mobile phone circuit board is the number of electronic waste is rising year by year,and the component part of waste mobile phone board with strong toxicity,if mishandled,the global cause irreparable damage to the ecological environment,on the other hand,waste mobile phone webmaster board headed by copper metal content is rich,is an invisible"Energy Mine".Therefore,the recycling of the metal on the waste mobile phone board,especially copper,has become a research hotspot.At present,the technology of recovering metal from mobile phone plate by wet method is widely used due to its high flexibility and high recovery rate.However,the chemical reagent in the test,such as improper treatment will produce serious secondary pollution to the environment.Therefore,in this paper,through the use of cleaning reagent-Ionic Liquid and electrolysis combined way,to explore efficient,energy-saving clean recovery of old mobile phone board on the copper technology.The work of this study and its main conclusions are as follows:（1）.Hno3-hf-hclo4 was used to conduct electrothermal plate digestion and pretreatment on the dismantled and broken waste mobile phone board,and ICP-MS was used to determine the metal composition in the waste mobile phone board.The copper content in the waste mobile phone board was the highest,about 83.31%.（2）.Taking copper leaching rate as the index,single factor experiment was conducted to explore the influencing factors of ionic liquid leaching of copper and explore its reaction control model.Draw the optimum leaching conditions for:BmimPF₆ add sodium chloride and hydrogen peroxide in 50℃leach,120 min,leaching rate of 22.61%,the leaching reaction control model for solid membrane,produce 19.8 kJ/mol,the lowest reaction activation energy,provide reference for selecting the appropriate Ionic Liquid.（3）.Taking the recovery rate of copper as the first evaluation index and the current efficiency as the reference index,single-factor test was designed to study the optimal composition of copper electrolyte and electrolysis conditions in common electrolytic deposition waste mobile phone plate.By means of SEM,EDS and XPS instrument analysis and test,the copper morphology and valence state composition of electrolytic recovery were studied.Test results:Best electrolysis condition:CuSO₄concentration:30g/L;NaCl concentration:40g/L;H₂SO₄ concentration:150g/L;Current size:0.5A;Electrolysis time:5h;WPCBs feed quantity:5g,the highest copper recovery rate of 81.24%.The current efficiency is69.12%.The deposited powder was dense and dendritic,with copper content of 81.03%,pure copper content of 62.06%,and the rest copper was in the form of CuCl.（4）.According to the single factor test results of the two groups above,the conductivity of Ionic Liquids with different volume percentages in the optimal combination electrolyte was studied,and Origin was used for digital fitting of the changes in time and temperature,and the results were as follows:When 1%EmimCl or BmimPF₆ was added,the conductivity decreased significantly,which was consistent with the Kohlraush relationship.When 1%EmimCl or 2%BmimPF₆ is added,the temperature coefficient is maximum and is minimum.At this time,the influence of volume percentage change on conductivity is weakened by temperature control.（5）.The influence of different volume percentage of BmimPF₆ addition on copper electrolysis recovery was studied under the optimal experimental parameter condition after the optimization of the test scheme.By means of SEM,EDS and XPS,the morphology and valence composition of copper recovered by electrolysis were studied.It is concluded that:When CuSO₄-NaCl-H₂SO₄-BmimPF₆ system join2%BmimPF₆,under 50℃of Cu recovery rate is highest,92.65%.The current efficiency is 79.99%.The obtained copper is almost all copper,accounting for99.64%.In the deposited powder,copper powder was obviously refined and the surface was denser and smoother.On the whole,this paper optimizes the previous schemes of purifying copper from waste mobile phone boards,explores the highest recovery rate and the best test conditions of copper electrolysis recovery under the action of the optimal ratio of Ionic Liquid and ordinary electrolyte,and establishes a feasible operation mode of copper electrolysis recovery based on ionic liquid.