Hydrogen Diffusion Anodes In Aluminum And Zinc Electrowinning

Hydrogen diffusion anode was applied in Zinc electrowinning for the traditional anode oxidation reaction of H2O replaced by the oxidation reaction of H2, which could save 50% energy for the whole Zinc electrowinning. and its research and application extension have the vital significance.This article has studied the gas diffusion anode energy conservation principle, Discusses preparation and principle of the porous carbon substrate, gas diffusion layer, gas catalyst layer, special membranes, introduced the testing principle of hydrogen diffusion anode performance, as well as the current efficiency, cell voltage of the impact of energy consumption of zinc electrowinning.The energy conservation principle of Hydrogen diffusion anode was studied and prepared in this paper. By the means of adding pore agent, the hydrogen diffusion anodes were made of activated carbon, carbon black, pore agent, caking agent, and catalyst by using hot press forming, which were made up of the porous carbon electrode, the diffusion layer, the catalyzed level and the special membrane. and have assembled the hydrogen diffusion anode. The manufacturing process was obtained.By using SEM the apparent morphology and pore morphology of the porous carbon electrodes were observed. And using the condition cut-and-try method, It was studied that the relationship between the kinds of pore agent, the size of pore agent and the size of activated carbon as well as the different mixture proportion of raw material and electrical property. Experimental results were as follows:the electrochemical properties of Hydrogen diffusion anodes with different pore formers were explained by steady polarization curves. The results showed that the electrochemical properties of Hydrogen diffusion anodes with NaCl is better, NaBr less, anhydrous Na2SO4 the least.he superficial appearance and pore structure of Hydrogen diffusion anodes with different activated charcoal particle size were explained by SEM. The results showed that Hydrogen diffusion anodes with 60 mesh NaCl is better, and the influence to its electrochemical properties by pore agent and activated charcoal properties were explained by steady polarization curves. The results showed that under the same process conditions the electrochemical properties and pore structure of Hydrogen diffusion anodes is improved significantly with additions of 60 mesh NaCl at 20% and 60 mesh activated charcoal at 55%.Based on the traditional Zinc electrowinning process, the influence to the current efficiency and the power consumption of zinc electrodeposition by the concentration of sulfuric acid, the current density, the temperature, the distance of heterospolar and the mixing speed as well as different time was studied with Hydrogen diffusion anode in place of the traditional Pb-Ag anode. By means of analysis and calculation to the slot voltage(V),current efficiency (η),power consumption(W) as well as the surface appearance of the cathode zinc explained under the different experimental conditions by SEM. The results showed that in the research of zinc electroplating using hydrogen diffusion anode material, In 240g H2SO4dm-3,at current densities of 2000A/m2,at 35℃, at mixing speed of 1000r/min as well as the central distance of heterospolar for 10mm, the current efficiency is highest, the energy saving effect is bettter. and crystal grain of the cathode zinc is tiny, the surface smooth, the quality of coating better. It is clear that Hydrogen diffusion anodes have the abroad superiority in energy saving as well as improving the quality of the cathode zinc and so on.