Leaching Vanadium-Rich Steel Slag Using Carbonated Water from a Domestic SodaStream

Vanadium is a “critical metal” that is predominantly produced from steelmaking slags using a salt-roast leach process that emits corrosive byproduct gases and a contaminated liquid discharge. Here, we describe a clean vanadium extraction method using the environmentally benign lixiviant–carbonated water. This method was found to be highly selective for dissolution of vanadium, manganese, and calcium over iron. By simply using saturated aqueous CO2 solutions produced in a domestic SodaStream, we have extracted vanadium from air-roasted slags with up to 50% efficiency. A modified Parr reactor was then used to achieve higher CO2 saturation pressures, resulting in vanadium extraction efficiencies up to 77%. Vanadium-bearing solids were precipitated from the leachate solutions and further processed to produce both vanadium metal and a V–Mn alloy. Our results demonstrate that carbonated water leaching represents a promising alternative green chemistry route to vanadium extraction from steel slags.