Electrochemical extraction of lead from urea-1-ethyl-3-methylimidazolium fluoride system containing PbO at 353 K
(1. Key Laboratory for Ecological Metallurgy of Multimetallic Mineral (Ministry of Education), Northeastern University, Shenyang 110819, China;
2. Department of Chemistry, Physics and Atmospheric Science, Jackson State University, Jackson, MS 39217, USA;
3. Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute & Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China;
4. State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China)
2. Department of Chemistry, Physics and Atmospheric Science, Jackson State University, Jackson, MS 39217, USA;
3. Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute & Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China;
4. State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China)
Abstract: To electrochemically extract Pb from PbO at room temperature, a new electrolyte, urea-1-ethyl-3- methylimidazolium fluoride (urea-[EMIM]F), was synthesized to dissolve PbO. Afterwards, the electrochemical behavior of Pb in this electrolyte was studied. The density, viscosity and conductivity of this electrolyte were investigated before electroextraction. The electrochemical behavior of Pb in the urea-[EMIM]F system was recorded via cyclic voltammograms, chronoamperometry and potentiostatic electrolysis. The results illustrate that Pb can be electrochemically extracted from PbO in this system at room temperature and that Pb reduction involves a quasireversible process and follows a one-step and two-electron transfer process. The reduction of Pb proceeds with a three-dimensional (3D) progressive model. With an increase in temperature, the onset potentials for Pb reduction shift anodically. The diffusion coefficient of Pb(II) is determined to be 6.88×10-10 cm2/s at 353 K. Additionally, spherical Pb particles are obtained after electrodeposition in the urea-[EMIM]F system via potentiostatic electrolysis.
Key words: Pb; ionic liquids; imidazolium fluoride; electrodeposition; viscosity