Study on separation and purification of titanium alloys (TC4-6Al-4V) by molten salt electrolysis

Abstract

With the widespread expansion of titanium applications and its significant increase in usage, the issue of recycling titanium resources after consumption has emerged. Focusing on titanium alloys with high usage, such as TC4 (Ti-6Al-4V), this article proposes a titanium separation and recovery method based on molten salt electrolysis. This method thoroughly analyzes the characteristics of elements in TC4 and electrochemical principles, ensuring that vanadium in the TC4 alloy does not undergo electrochemical dissolution when the electrolysis potential is below 0.3 V vs Pt. Subsequently, through electrochemical analysis, it was discovered that the precipitation of aluminum ions is influenced by concentration. Therefore, by controlling the concentration of aluminum in the eutectic molten salt, such as increasing the electrolyte concentration and shortening the electrolysis time, the precipitation of aluminum can be effectively avoided. Under the experimental conditions mentioned above, vanadium elements deposit at the bottom of the crucible in the form of anode slime, while aluminum dissolves and remains in the electrolyte. Meanwhile, titanium ions in the cathode region undergo electron reduction and deposit in the cathode area in the form of titanium, thus achieving precise separation of alloy elements. Experimental verification shows that the purity of the obtained titanium reaches 99.17 atomic percent. Therefore, this molten salt electrolysis method, which combines the physical properties of alloy elements with electrochemical principles, not only provides a new perspective for the separation and recovery of titanium and other critical metals, but also offers new research directions for the recovery technology of other alloy elements.