| For the production of zinc hydrometallurgy in industry, the lead-based alloy anode is widely used because of the high corrosion resistance and availability in the high concentration acid system. However, there are still some problems for the lead-based alloy anode, such as the high energy loss during the zinc electrowinning process. As well, the poor creep property and the lead anode is etched into the electrolyte which will reduce the quality of deposited zinc. To solve those problems, new anode materials have been widely investigated to replace the lead anode, multi lead-based alloy anode, titanium based DSA and noble metal anodes for example. The disadvantags for these anodes are the short life time and high cost. Now it still is an important issue to develop novel anode in the zinc hydrometallurgy. PANI based anode has been investigated for a long time. The preparation technology and the optimum preparation parameter of two cerium oxide/tungsten carbide (CeO2/WC), polyaniline/two cerium oxide/tungsten carbide (PANI/CeO2/WC), carbon fiber/polyaniline (PANI/carbon fiber), carbon fiber/polyaniline/two cerium oxide/tungsten carbide (carbon fiber/PANI/CeO2/WC) composite material were studied in thesis, and the complex mechanism of composite materials were discussed. At the same time, the electrochemical performance of composite material was systemly researched in acid zinc system. And tank voltage, working life of anode, cathode zinc quality of the carbon fiber/PANI/CeO2/WC anode were futher studied in simulation experiment of zinc electrowinning.These composites were characterized by means of FTIR, XRD, SEM, XPS and Raman et.al. The electro-properties of anode have been researched by cyclic voltammetry, polarization curves, A.C impedance et.al. The main results are shown as following:(1) CeO2/WC composite is better than the pure CeO2and WC with electrochemical activity, and when the content of CeO2is65wt%, under200A/m2current density the constant polarization potentials as low as1.31V. CeO2/WC composite is not simple physical hybrid with WC and CeO2, new species was formed between them.(2) When the CeO2/WC relative to the aniline monomer volume is0.075g/mL, polymerization time was4h, the electrical conductivity and electrochemical performance of PANI/CeO2/WC composite are best. In PANI/CeO2/WC composites, inorganic solid particles can increases the order and crystallinity degree of molecular chain of PANI, also make CeO2stable exist in polymerization process of aniline.(3) When the release of aniline and carbon fiber was3:7, the content of PVP was5%, the polymerization time was6h, the comprehensive properties of carbon fiber/PANI composite materials was the most ideal; electrical properties study showed that addition of carbon fiber can make the conductivity of material is reduced, but can increase the mechanical strength of polyaniline anode.(4) The service life is longest of carbon fiber/PANI/CeO2/WC anodes when proportion of carbon fiber/PANI composites and PANI/CeO2/WC composites for1:9.(5) In electrolytic experiment, stable cell voltage of carbon fiber/polyaniline anode are all smaller, but the carbon fiber/PANI/CeO2/WC composite anode’s minimum, low to2.6V, indicading the obvious synergistic effect between WC and CeO2.(6) The failure anode is still the eigenstate polyaniline, so it can be recyclinged and repreparation anode using failure anode sample, green environmental protection. The real reason for it failure is:(a) the crack of the anode at surface and side changese more and deeper, and anode short-circuit.(b) Contact point of metal wire and PANI base wafer become a heating wire caused by short circuit. |
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