Electrochemical Reduction of Silicon Oxide and Codeposition of Al-Si Alloy from Cryolite Molten Salt

The preparation of high-purity and high-value alloys is of great significance to industrial production. The purpose of this study is to explore the process of producing aluminum-silicon (Al-Si) alloy by the electrochemical Al-Si eutectoid method. The electrochemical behavior of aluminum and silicon on tungsten electrode was studied by cyclic voltammetry and galvanostatic chronopotentiometry. The effect of SiO 2 addition on the eutectoid behavior of Al and Si was studied. The results show that the precipitation potential of Al is about –1.35 V (versus Pt), and the initial precipitation potential of Si is about –0.8 V (versus Pt). The precipitation process of silicon includes two reduction stages. In addition, the precipitation of Si is a quasireversible reaction controlled by diffusion process. Finally, Al-Si alloy was obtained by potentiostatic electrodeposition at –1.8 V potential, indicating that Al and Si would codeposit at this potential.