Additive Gelatin In The Copper Electrolysis In Electrochemical Behavior

This paper study on the gelatin of which electrochemistry process of electrolytic refining, using different test method of electrochemistry is as Tafel curve,cathodic polarization,electricity impedance,chronopotentiometry and so on,research of gelatin is on characteristic of reaction on copper electrode and effect of polarization of cathode systemic. By the method of electricity impedance, gelatin on kinetics of electrolytic refining was researched.. By changing the current density, temperature and concentration of gelatin, found the decomposition law with time. The main result is that:The gelatin is the most important additive in copper electrolytic refining process. Use gelatin could control the corrosion of copper effective, and efficiency of corrosion is up by additive increased, chargemigration was less effective by gelatin, but exchange current density was reduced. Gelatin control the kinetics of reduction of Cu2+,gelatinous membrane was formed by gelatin that covered the position of apophysis, in order to make it inactive.Make use of Tafel curve and AC impedance to research of gelatin on kinetics of reduction of cathode, by the cathodic polarization curve and parameters of kinetics, the reduction of gelatin on copper electrode is diffusion control; the absorption of gelatin on copper electrode was controlled by diffusion, add along with increase of concentration of gelatin.By changing the current density, temperature and concentration of gelatin, having a electrochemistry tests after adding gelatin 2min, studied under different conditions the process of copper electrorefining's cathode polarization after add gelatin between the 2-12min, effects on electrode/liquid interface reaction kinetics and the cathode wettability, determine the electrochemical behavior of gelatin in electrolytic copper. Research result revealed that reaction of copper electrode belongs to mix control process, with the increase of concentration of gelatin, gelatin has good wetting, in copper electrolytic refining act as wetting agents,which can guarantee in the cathode copper without stoma and obtain a smooth and compact cathode copper, gelatin adsorption in the copper electrode surface is diffusion control.In different time intervals electrorefining for 5min at 60℃separately, the electrolytic solution contained 45 g dm-3 Cu2+ and 165 g dm-3 H2SO4 and controlled the current density at 300A m-2.Employed metallurgical microscope analysis the amount of crystalline particle and the crystalline size of the surface of cathode coppers. Research result revealed that after adding gelatin 50-60min, obtain compact and smooth cathode copper, the maximum and minimum grain size is 14.99nm and 6.97nm separately, average size is 13.13 nm, grain density is 4.24×107/mm2.