Preparation and performance of an Al/TiB_2 + 10%Ti_4O_7/β-PbO_2 as a composite anodic material for electrowinning of non-ferrous metals

摘要

Electrodes are the key material in the electrolysis of non-ferrous metals, and their selection and preparation can be a difficult problem in the hydrometal-lurgical industry. In this paper, starting from the selection of electrode materials and structural design, an Al/TiB_2 + 10％Ti4O_7 -coating composite material was prepared by plasma spraying technology, and a β-PbO_2 coating was prepared by electrochemical deposition. The phase composition of the coating was analyzed by X-ray diffractometer, and the structure of the coating was observed by scanning electron microscopy. Results show that the electrode prepared by electrodeposition at a current density of 0.03 A cm~(-2) has a more compact structure and more uniform grain size. Through steady-state polarization curve, cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy, the electrochemical performance of the electrode was studied. Through porosity measurements, it was found that the composite electrode material prepared by the plasma spraying method under the parameters of a spraying power of 36 kW, powder feeding rate of 30 g/min, spraying distance of 105 mm, and argon gas flow rate of 2.6 m~3/h greatly reduces the charge resistance in the double-layer structure on the electrode surface, thereby accelerating the charge transfer rate. Plasma spraying and electrochemical deposition have been used to successfully prepare Al/TiB_2 + 10%Ti_4O_7/β-PbO_2 composite electrode materials with good corrosion resistance and electrochemical catalytic activity. Compared to Ti/β-PbO_2 and Pb-(0.5 wt%)Ag/β-PbO_2, the corrosion resistance and polarization potential increased by 83.6% and 93.0% and negatively shifted by 517.37 mV and 587.12 mV, respectively, and the catalytic activity was also significantly improved.