Abstract
As part of its efforts to maximize resource recovery, the Bureau of Mines conducted studies to recover valuable byproducts from western phosphate beneficiation tailings. Potential byproducts include phosphorus, vanadium, and uranium. The objective was to determine roasting and leaching conditions for maximum dissolution of vanadium from tailings containing approximately 13 pct p2o5 and 0.23 pct V. Sulfuric acid leaching tests were conducted with the tailings either as a dilute suspension, dried, or in a roasted condition with or without nacl added during roasting. More than 90 pct of the vanadium was dissolved by roasting at 850 deg c for 120 min with 8- pct nacl and leaching at 75 deg c for 120 min with an excess of 2n h2so4. By roasting without nacl and avoiding the difficulties of the chloride impurity, nearly 80-pct vanadium dissolution was achieved with an 800 deg c roast for 180 min. Quadratic regression equations were derived to relate vanadium dissolution to roasting and leaching conditions.
