Process for obtaining vanadium oxide from a gasifier slag field

A process for obtaining vanadium oxide from gasifier slag having vanadium component, the process comprising the following steps:

• a. pulverizing the gasifier slag to a particle size of 75 μm to obtain pulverized slag;
• b. blending the pulverized slag with water and sodium carbonate to obtain a slurry;
• wherein the amount of sodium carbonate is 30 wt % of the total slag;
• c. drying the slurry at temperature of 120° C. to remove water therefrom;
• d. roasting the slurry in the presence of air, at 900° C. to obtain a roasted slag;
• e. leaching the roasted slag with water to obtain a first filtrate comprising the vanadium component;
• wherein the ratio of water to the roasted slag is 3:1;
• f. separating a silica component from the first filtrate using magnesium nitrate to obtain a second filtrate;
• wherein the amount of magnesium nitrate is 15 wt % of the total slag;
• g. reacting the second filtrate with an ammonium sulphate to obtain ammonium metavanadate in the form of a precipitate;
• wherein the amount of ammonium sulphate is 15 wt % of the total slag;
• and
• h. separating the precipitate and calcining at 450° C. to obtain vanadium oxide having purity greater than 99%.