The separation of iron from kaolin clay solutions using electro deposition was studied. Electrochemical studies of the iron electro-deposition were performed using the techniques of cyclic voltammetry, chronopotentiometry and chronoamperometry on a silver rotating disk electrode (RDE) as a working electrode. The effect of the kaolin solution pretreatment with ultrasonic method on the electrochemical reduction processes was studied. The influence of the disk speed of the electro-deposition performances was also studied. The morphology of the surface of the electro-deposit was observed by SEM. It was found that the ultrasonic pretreatment has an important effect on the reduction processes and on the morphology of the electrodeposited sample. The chemical composition of the electrode-posit was characterized by atomic absorption and ICP-ToFMS. It was shown that Fe2O3 content in the clay was 0.6% (weight). The voltammetric studies revealed that, during the electrochemical reduction processes of the kaolin solution, the iron reduction peaks were observed in the potential range from - 0.52V to -2.0V (E vs. SCE). Subsequently, the chronopotentiometry study showed that when a current of - 0.09A is applied to the electrochemical cell, the reduction of iron species occurred. It was also found that the variation of the amount of the electrodeposited iron is, of course, significantly dependent of the speed of the working electrode. For an electrode speed rate ranged from 1500 to 6500 rpm (revolutions per minute), an optimum amount of the electro deposited iron was obtained for an electrode speed of about 4000 rpm.
kaolin, reduction, electrochemistry, iron
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